Publikacje Katedry w serwisie Baza Wiedzy UMCS
2024
Paola De Padova and Mariusz Krawiec.
Dirac materials beyond graphene.
In Tapash Chakraborty (ed.). Encyclopedia of Condensed Matter Physics (Second Edition). Academic Press, January 2024, pages 329-343.
Abstract The meaning of Dirac's materials, in its most common sense, has been explored by taking a quick look at the Dirac equation, as originally formulated, and subsequently applied to the structure of condensed matter, of two-dimensional (2D) materials beyond graphene. What makes 2D materials exceptional, as well as the discovery of new allotropic forms, is the possibility of having extraordinary physical properties, such as energy dispersion, which immediately can correlate electrons to their being Dirac fermions. Through experimental and theoretical examples, we report structural and electronic properties of 2D materials beyond graphene, which today represent the frontier of condensed matter physics. URL, DOI BibTeX@incollection{DEPADOVA2024329, title = "Dirac materials beyond graphene", editor = "Tapash Chakraborty", booktitle = "Encyclopedia of Condensed Matter Physics (Second Edition)", publisher = "Academic Press", edition = "Second Edition", address = "Oxford", pages = "329-343", year = 2024, month = "Jan", isbn = "978-0-323-91408-6", doi = "https://doi.org/10.1016/B978-0-323-90800-9.00169-4", url = "https://www.sciencedirect.com/science/article/pii/B9780323908009001694", author = "Paola {De Padova} and Mariusz Krawiec", keywords = "ARPES, Artificial 2D materials beyond graphene, Band structure, Constant energy contour, DFT, Dirac cones, Dirac equation, Dirac fermions, Dirac materials, Elemental 2D materials, Honeycomb lattice, K and K′ points, Linear dispersion band, Massless fermions, Multilayer, Reciprocal space, STM, STS, TMD, Topological insulators, Van-Hove singularities", abstract = "The meaning of Dirac's materials, in its most common sense, has been explored by taking a quick look at the Dirac equation, as originally formulated, and subsequently applied to the structure of condensed matter, of two-dimensional (2D) materials beyond graphene. What makes 2D materials exceptional, as well as the discovery of new allotropic forms, is the possibility of having extraordinary physical properties, such as energy dispersion, which immediately can correlate electrons to their being Dirac fermions. Through experimental and theoretical examples, we report structural and electronic properties of 2D materials beyond graphene, which today represent the frontier of condensed matter physics." }
2023
Irena Padniuk, Otilia Stoica, Rafal Zuzak, Remi Blieck, Mariusz Krawiec, Szymon Godlewski and Antonio M Echavarren.
On surface synthesis of an eleven-ring sulfur-doped nonacene.
Chem. Commun., pages -, December 2024.
Abstract Dithienoacenes with a heptacene core, heptaceno[2,3-b:11,12-b′]bis[1]benzothiophene, have been synthesized through the combination of solution and surface assisted chemistry. The atomic composition, structural arrangement and electronic properties of the molecules on the Au(111) surface have been deeply explored by non-contact atomic force microscopy (nc-AFM), bond-resolved scanning tunnelling microscopy (BR-STM) and scanning tunneling spectroscopy (STS) corroborated by density functional theory (DFT) calculations. Our combined experiments reveal modifications induced by sulfur substitution. URL, DOI BibTeX@article{D3CC05486A, author = "Padniuk, Irena and Stoica, Otilia and Zuzak, Rafal and Blieck, Remi and Krawiec, Mariusz and Godlewski, Szymon and Echavarren, Antonio M.", title = "On surface synthesis of an eleven-ring sulfur-doped nonacene", journal = "Chem. Commun.", year = 2024, month = "Dec", pages = "-", publisher = "The Royal Society of Chemistry", doi = "10.1039/D3CC05486A", url = "http://dx.doi.org/10.1039/D3CC05486A", abstract = "Dithienoacenes with a heptacene core{,} heptaceno[2{,}3-b:11{,}12-b′]bis[1]benzothiophene{,} have been synthesized through the combination of solution and surface assisted chemistry. The atomic composition{,} structural arrangement and electronic properties of the molecules on the Au(111) surface have been deeply explored by non-contact atomic force microscopy (nc-AFM){,} bond-resolved scanning tunnelling microscopy (BR-STM) and scanning tunneling spectroscopy (STS) corroborated by density functional theory (DFT) calculations. Our combined experiments reveal modifications induced by sulfur substitution." }Agnieszka Stȩpniak-Dybala, Tomasz Jaroch, Mariusz Krawiec, Piotr Dróżdż, Mariusz Gołȩbiowski and Ryszard Zdyb.
Peculiar Structural Phase of a Single-Atom-Thick Layer of Antimony.
Nano Letters 23(21):9894-9899, October 2023.
Abstract Using molecular beam epitaxy, a new structural phase of a single atom thick antimony layer has been synthesized on the W(110) surface. Scanning tunneling microscopy measurements reveal an atomically resolved structure with a perfectly flat surface and unusually large unit cell. The structure forms a well-ordered continuous film with a lateral size in the range of several millimeters, as revealed by low energy electron microscopy and diffraction experiments. The results of density functional theory calculations confirm the formation of a new phase of single-atom-thick antimony film without the buckling characteristic for the known phases of antimonene. The presented results demonstrate a substrate-tuned approach in the preparation of new structural phases of 2D materials. URL, DOI BibTeX@article{doi:10.1021/acs.nanolett.3c02847, author = "Stȩpniak-Dybala, Agnieszka and Jaroch, Tomasz and Krawiec, Mariusz and Dróżdż, Piotr and Gołȩbiowski, Mariusz and Zdyb, Ryszard", title = "Peculiar Structural Phase of a Single-Atom-Thick Layer of Antimony", journal = "Nano Letters", volume = 23, number = 21, pages = "9894-9899", year = 2023, month = "Oct", doi = "10.1021/acs.nanolett.3c02847", note = "PMID: 37861984", url = "https://doi.org/10.1021/acs.nanolett.3c02847", eprint = "https://doi.org/10.1021/acs.nanolett.3c02847", abstract = "Using molecular beam epitaxy, a new structural phase of a single atom thick antimony layer has been synthesized on the W(110) surface. Scanning tunneling microscopy measurements reveal an atomically resolved structure with a perfectly flat surface and unusually large unit cell. The structure forms a well-ordered continuous film with a lateral size in the range of several millimeters, as revealed by low energy electron microscopy and diffraction experiments. The results of density functional theory calculations confirm the formation of a new phase of single-atom-thick antimony film without the buckling characteristic for the known phases of antimonene. The presented results demonstrate a substrate-tuned approach in the preparation of new structural phases of 2D materials." }Mieczysław Jałochowski and Tomasz Kwapiński.
Distribution of Electron Density in Self-Assembled One-Dimensional Chains of Si Atoms.
Materials 16(17), September 2023.
Abstract Scanning tunneling microscopy measurements of height profiles, along the chains of Si atoms on the terrace edges of a perfectly ordered Si(553)-Au surface, reveal an STM bias-dependent mixed periodicity with periods of one, two and one and a half lattice constants. The simple linear chain model usually observed with STM cannot explain the unexpected fractional periodicity in the height profile. It was found that the edge Si chain stands for, in fact, a zigzag structure, which is composed of two neighboring rows of Si atoms and was detected in the STM experiments. Tight-binding calculations of the local density of states and charge occupancy along the chain explain the voltage-dependent modulations of the STM profiles and show that oscillation periods are determined mainly by the surface and STM tip Fermi energies. URL, DOI BibTeX@article{ma16176044, author = "Jałochowski, Mieczysław and Kwapiński, Tomasz", title = "Distribution of Electron Density in Self-Assembled One-Dimensional Chains of Si Atoms", journal = "Materials", volume = 16, year = 2023, month = "Sep", number = 17, article-number = 6044, url = "https://www.mdpi.com/1996-1944/16/17/6044", pubmedid = 37687737, issn = "1996-1944", abstract = "Scanning tunneling microscopy measurements of height profiles, along the chains of Si atoms on the terrace edges of a perfectly ordered Si(553)-Au surface, reveal an STM bias-dependent mixed periodicity with periods of one, two and one and a half lattice constants. The simple linear chain model usually observed with STM cannot explain the unexpected fractional periodicity in the height profile. It was found that the edge Si chain stands for, in fact, a zigzag structure, which is composed of two neighboring rows of Si atoms and was detected in the STM experiments. Tight-binding calculations of the local density of states and charge occupancy along the chain explain the voltage-dependent modulations of the STM profiles and show that oscillation periods are determined mainly by the surface and STM tip Fermi energies.", doi = "10.3390/ma16176044" }Marcin Łapiński, Piotr Dróżdż, Mariusz Gołębiowski, Piotr Okoczuk, Jakub Karczewski, Marta Sobanska, Aleksiej Pietruczik, Zbigniew R Zytkiewicz, Ryszard Zdyb, Wojciech Sadowski and Barbara Kościelska.
Thermal Instability of Gold Thin Films.
Coatings 13(8), July 2023.
Abstract The disintegration of a continuous metallic thin film leads to the formation of isolated islands, which can be used for the preparation of plasmonic structures. The transformation mechanism is driven by a thermally accelerated diffusion that leads to the minimalization of surface free energy in the system. In this paper, we report the results of our study on the disintegration of gold thin film and the formation of nanoislands on silicon substrates, both pure and with native silicon dioxide film. To study the processes leading to the formation of gold nanostructures and to investigate the effect of the oxide layer on silicon diffusion, metallic film with a thickness of 3 nm was deposited by molecular beam epitaxy (MBE) technique on both pure and oxidized silicon substrates. Transformation of the thin film was observed by low-energy electron microscopy (LEEM) and a scanning electron microscope (SEM), while the nanostructures formed were observed by atomic force microscope (AFM) method. Structural investigations were performed by low-energy electron diffraction (LEED) and X-ray photoelectron spectroscopy (XPS) methods. Our experiments confirmed a strong correlation between the formation of nanoislands and the presence of native oxide on silicon substrates. URL, DOI BibTeX@article{coatings13081306, author = "Łapiński, Marcin and Dróżdż, Piotr and Gołębiowski, Mariusz and Okoczuk, Piotr and Karczewski, Jakub and Sobanska, Marta and Pietruczik, Aleksiej and Zytkiewicz, Zbigniew R. and Zdyb, Ryszard and Sadowski, Wojciech and Kościelska, Barbara", title = "Thermal Instability of Gold Thin Films", journal = "Coatings", volume = 13, year = 2023, month = "Jul", number = 8, article-number = 1306, url = "https://www.mdpi.com/2079-6412/13/8/1306", issn = "2079-6412", abstract = "The disintegration of a continuous metallic thin film leads to the formation of isolated islands, which can be used for the preparation of plasmonic structures. The transformation mechanism is driven by a thermally accelerated diffusion that leads to the minimalization of surface free energy in the system. In this paper, we report the results of our study on the disintegration of gold thin film and the formation of nanoislands on silicon substrates, both pure and with native silicon dioxide film. To study the processes leading to the formation of gold nanostructures and to investigate the effect of the oxide layer on silicon diffusion, metallic film with a thickness of 3 nm was deposited by molecular beam epitaxy (MBE) technique on both pure and oxidized silicon substrates. Transformation of the thin film was observed by low-energy electron microscopy (LEEM) and a scanning electron microscope (SEM), while the nanostructures formed were observed by atomic force microscope (AFM) method. Structural investigations were performed by low-energy electron diffraction (LEED) and X-ray photoelectron spectroscopy (XPS) methods. Our experiments confirmed a strong correlation between the formation of nanoislands and the presence of native oxide on silicon substrates.", doi = "10.3390/coatings13081306" }T Kwapiński.
One-dimensional transient crystals.
Phys. Rev. B 107:035422, January 2023.
Abstract A phase of solid state matter which exists in time dimension is investigated theoretically for a linear chain of quantum dots or atomic sites using the evolution operator technique and the Laplace transform technique.. The studies focus on the spectral density of states (DOS) function and its modifications after a sudden quench in the system. It is shown that this function reveals a very regular structure which oscillates in time and which corresponds to the stationary DOS of one-dimensional crystals. Thus, such a system stands for a transient crystal material which exists in time dimension but appears only for a short period and suddenly vanishes. Moreover, we observe different impulse propagation velocities due to the local DOS inertia, i.e., it is more difficult to rebuild a many-peaked structure of DOS related to longer chains. We also show that the transient crystal pattern in a linear chain can be observed for real electrodes characterized by the van Hove singularities or by a flat spectral density. URL, DOI BibTeX@article{PhysRevB.107.035422, title = "One-dimensional transient crystals", author = "Kwapiński, T.", journal = "Phys. Rev. B", volume = 107, issue = 3, pages = 035422, numpages = 9, year = 2023, month = "Jan", publisher = "American Physical Society", doi = "10.1103/PhysRevB.107.035422", url = "https://link.aps.org/doi/10.1103/PhysRevB.107.035422", abstract = "A phase of solid state matter which exists in time dimension is investigated theoretically for a linear chain of quantum dots or atomic sites using the evolution operator technique and the Laplace transform technique.. The studies focus on the spectral density of states (DOS) function and its modifications after a sudden quench in the system. It is shown that this function reveals a very regular structure which oscillates in time and which corresponds to the stationary DOS of one-dimensional crystals. Thus, such a system stands for a transient crystal material which exists in time dimension but appears only for a short period and suddenly vanishes. Moreover, we observe different impulse propagation velocities due to the local DOS inertia, i.e., it is more difficult to rebuild a many-peaked structure of DOS related to longer chains. We also show that the transient crystal pattern in a linear chain can be observed for real electrodes characterized by the van Hove singularities or by a flat spectral density." }
2022
Paweł Nita, Marek Dachniewicz, Mieczysław Jałochowski, Krisztián Palotás and Mariusz Krawiec.
Template Driven Self-Assembly of the Pentacene Structure on the Si(553)-Pb Surface.
The Journal of Physical Chemistry C 126(41):17738-17745, October 2022.
Abstract The self-assembly of the pentacene molecules on the Pb-ordered Si(553) surface is studied with scanning tunneling microscopy and density functional theory methods. Within the surface coverage up to a single monolayer, pentacene was found to form two different chain-like structures. They vary in molecular density, but both exhibit long-range, one-dimensional ordering with longer molecular axes aligned along step edges. The low-density phase consists of single discontinuous molecular rows and adapts the template surface periodicity, while the high-density phase features triple molecular chains with the unit cell determined by the length of the pentacene molecules. Such an arrangement of the molecules is controlled by a subtle balance between molecule–molecule and molecule–substrate interactions. URL, DOI BibTeX@article{doi:10.1021/acs.jpcc.2c05308, author = "Nita, Paweł and Dachniewicz, Marek and Jałochowski, Mieczysław and Palotás, Krisztián and Krawiec, Mariusz", title = "Template Driven Self-Assembly of the Pentacene Structure on the Si(553)-Pb Surface", journal = "The Journal of Physical Chemistry C", volume = 126, number = 41, pages = "17738-17745", year = 2022, month = "Oct", doi = "10.1021/acs.jpcc.2c05308", url = "https://doi.org/10.1021/acs.jpcc.2c05308", eprint = "https://doi.org/10.1021/acs.jpcc.2c05308", abstract = "The self-assembly of the pentacene molecules on the Pb-ordered Si(553) surface is studied with scanning tunneling microscopy and density functional theory methods. Within the surface coverage up to a single monolayer, pentacene was found to form two different chain-like structures. They vary in molecular density, but both exhibit long-range, one-dimensional ordering with longer molecular axes aligned along step edges. The low-density phase consists of single discontinuous molecular rows and adapts the template surface periodicity, while the high-density phase features triple molecular chains with the unit cell determined by the length of the pentacene molecules. Such an arrangement of the molecules is controlled by a subtle balance between molecule–molecule and molecule–substrate interactions." }P Sagan, I V Hadzaman, V D Popovych, R Mroczka, A Krzyszczak, M Wiertel and D Chocyk.
Growth morphology and phase composition of hierarchically self-organized oxyspinel composite films deposited by radio frequency magnetron sputtering.
Ceramics International 48(17):25236-25245, July 2022.
Abstract Multicomponent Al0.1Si0,05Ti0,1Mn1.45Co0.7Ni0.6O4 oxyspinel solid solution ceramics was synthesized to be subsequently used as a target for the deposition of thin films onto silicon and metallized silicon substrates by means of radio frequency sputtering method. Temporal evolution of chemical and phase compositions of the deposited layers, as well as their structure and surface morphology for the different substrate temperatures, have been systematically investigated using energy dispersive X-ray (EDS) analysis, secondary ion mass spectroscopy (SIMS) profiling, Raman spectroscopy, and atomic force microscopy (AFM). The samples revealed a uniform chemical composition throughout their whole depth, corresponding well with the formula unit of the spinel. Across the film depth, progressive developing of a self-organized, two-scale hierarchical composite structure was observed, which is composed of the main oxide grains decorated with spinel nanocrystallites. URL, DOI BibTeX@article{SAGAN202225236, title = "Growth morphology and phase composition of hierarchically self-organized oxyspinel composite films deposited by radio frequency magnetron sputtering", journal = "Ceramics International", volume = 48, number = 17, pages = "25236-25245", year = 2022, month = "July", issn = "0272-8842", doi = "https://doi.org/10.1016/j.ceramint.2022.05.188", url = "https://www.sciencedirect.com/science/article/pii/S027288422201759X", author = "P. Sagan and I.V. Hadzaman and V.D. Popovych and R. Mroczka and A. Krzyszczak and M. Wiertel and D. Chocyk", keywords = "Films, Magnetron sputtering, X-ray methods, Spinels", abstract = "Multicomponent Al0.1Si0,05Ti0,1Mn1.45Co0.7Ni0.6O4 oxyspinel solid solution ceramics was synthesized to be subsequently used as a target for the deposition of thin films onto silicon and metallized silicon substrates by means of radio frequency sputtering method. Temporal evolution of chemical and phase compositions of the deposited layers, as well as their structure and surface morphology for the different substrate temperatures, have been systematically investigated using energy dispersive X-ray (EDS) analysis, secondary ion mass spectroscopy (SIMS) profiling, Raman spectroscopy, and atomic force microscopy (AFM). The samples revealed a uniform chemical composition throughout their whole depth, corresponding well with the formula unit of the spinel. Across the film depth, progressive developing of a self-organized, two-scale hierarchical composite structure was observed, which is composed of the main oxide grains decorated with spinel nanocrystallites." }Irena Izydorczyk, Otilia Stoica, Mariusz Krawiec, Rémi Blieck, Rafal Zuzak, Marcin Stępień, Antonio M Echavarren and Szymon Godlewski.
On-surface synthesis of a phenylene analogue of nonacene.
Chem. Commun., pages -, March 2022.
Abstract Cyclobuta[1,2-b:3,4-b′]ditetracene – an analogue of nonacene with a cyclobutadiene unit embedded in the central part has been synthesized by the combination of solution and on-surface chemistry. The atomic structure and electronic properties of the product on Au(111) have been determined by high resolution scanning tunnelling microscopy/spectroscopy corroborated by density functional theory calculations. Structural and magnetic parameters derived from theoretical calculations reveal that π conjugation is dominated by radialene-type contribution, with an admixture of cyclobutadiene-like antiaromaticity. URL, DOI BibTeX@article{D2CC00479H, author = "Izydorczyk, Irena and Stoica, Otilia and Krawiec, Mariusz and Blieck, Rémi and Zuzak, Rafal and Stępień, Marcin and Echavarren, Antonio M. and Godlewski, Szymon", title = "On-surface synthesis of a phenylene analogue of nonacene", journal = "Chem. Commun.", year = 2022, month = "Mar", pages = "-", publisher = "The Royal Society of Chemistry", doi = "10.1039/D2CC00479H", url = "http://dx.doi.org/10.1039/D2CC00479H", abstract = "Cyclobuta[1{,}2-b:3{,}4-b′]ditetracene – an analogue of nonacene with a cyclobutadiene unit embedded in the central part has been synthesized by the combination of solution and on-surface chemistry. The atomic structure and electronic properties of the product on Au(111) have been determined by high resolution scanning tunnelling microscopy/spectroscopy corroborated by density functional theory calculations. Structural and magnetic parameters derived from theoretical calculations reveal that π conjugation is dominated by radialene-type contribution{,} with an admixture of cyclobutadiene-like antiaromaticity." }David Garagnani, Paola De Padova, Carlo Ottaviani, Claudio Quaresima, Amanda Generosi, Barbara Paci, Bruno Olivieri, Mieczysław Jałochowski and Mariusz Krawiec.
Evidence of sp2-like Hybridization of Silicon Valence Orbitals in Thin and Thick Si Grown on α-Phase Si(111)√3 × √3R30°-Bi.
Materials 15(5), February 2022.
Abstract One-monolayer (ML) (thin) and 5-ML (thick) Si films were grown on the α-phase Si(111)√3 × √3R30°-Bi at a low substrate temperature of 200 °C. Si films have been studied in situ by reflection electron energy loss spectroscopy (REELS) and Auger electron spectroscopy, as a function of the electron beam incidence angle α and low-energy electron diffraction (LEED), as well as ex situ by grazing incidence X-ray diffraction (GIXRD). Scanning tunneling microscopy (STM), and scanning tunneling spectroscopy (STS) were also reported. The REELS spectra, taken at the Si K absorption edge (~1.840 KeV), reveal the presence of two distinct loss structures attributed to transitions 1s→π* and 1s→σ* according to their intensity dependence on α, attesting to the sp2-like hybridization of the silicon valence orbitals in both thin and thick Si films. The synthesis of a silicon allotrope on the α-phase of Si(111)√3 × √3R30°-Bi substrate was demonstrated by LEED patterns and GIXRD that discloses the presence of a Si stack of 3.099 (3) Å and a √3 × √3 unit cell of 6.474 Å, typically seen for multilayer silicene. STM and STS measurements corroborated the findings. These measurements provided a platform for the new √3 × √3R30° Si allotrope on a Si(111)√3 × √3 R30°-Bi template, paving the way for realizing topological insulator heterostructures from different two-dimensional materials, Bi and Si. URL, DOI BibTeX@article{ma15051730, author = "Garagnani, David and De Padova, Paola and Ottaviani, Carlo and Quaresima, Claudio and Generosi, Amanda and Paci, Barbara and Olivieri, Bruno and Jałochowski, Mieczysław and Krawiec, Mariusz", title = "Evidence of sp2-like Hybridization of Silicon Valence Orbitals in Thin and Thick Si Grown on α-Phase Si(111)√3 × √3R30°-Bi", journal = "Materials", volume = 15, year = 2022, month = "Feb", number = 5, article-number = 1730, url = "https://www.mdpi.com/1996-1944/15/5/1730", issn = "1996-1944", abstract = "One-monolayer (ML) (thin) and 5-ML (thick) Si films were grown on the α-phase Si(111)√3 × √3R30°-Bi at a low substrate temperature of 200 °C. Si films have been studied in situ by reflection electron energy loss spectroscopy (REELS) and Auger electron spectroscopy, as a function of the electron beam incidence angle α and low-energy electron diffraction (LEED), as well as ex situ by grazing incidence X-ray diffraction (GIXRD). Scanning tunneling microscopy (STM), and scanning tunneling spectroscopy (STS) were also reported. The REELS spectra, taken at the Si K absorption edge (~1.840 KeV), reveal the presence of two distinct loss structures attributed to transitions 1s→π* and 1s→σ* according to their intensity dependence on α, attesting to the sp2-like hybridization of the silicon valence orbitals in both thin and thick Si films. The synthesis of a silicon allotrope on the α-phase of Si(111)√3 × √3R30°-Bi substrate was demonstrated by LEED patterns and GIXRD that discloses the presence of a Si stack of 3.099 (3) Å and a √3 × √3 unit cell of 6.474 Å, typically seen for multilayer silicene. STM and STS measurements corroborated the findings. These measurements provided a platform for the new √3 × √3R30° Si allotrope on a Si(111)√3 × √3 R30°-Bi template, paving the way for realizing topological insulator heterostructures from different two-dimensional materials, Bi and Si.", doi = "10.3390/ma15051730" }Tomasz Jaroch and Ryszard Zdyb.
Temperature-Dependent Growth and Evolution of Silicene on Au Ultrathin Films—LEEM and LEED Studies.
Materials 15(4), February 2022.
Abstract The formation and evolution of silicene on ultrathin Au films have been investigated with low energy electron microscopy and diffraction. Careful control of the annealing rate and temperature of Au films epitaxially grown on the Si(111) surface allows for the preparation of a large scale, of the order of cm2, silicene sheets. Depending on the final temperature, three stages of silicene evolution can be distinguished: (i) the growth of the low buckled phase, (ii) the formation of a layered heterostructure of the low buckled and planar phases of silicene and (iii) the gradual destruction of the silicene. Each stage is characterized by its unique surface morphology and characteristic diffraction patterns. The present study gives an overview of structures formed on the surface of ultrathin Au films and morphology changes between room temperature and the temperature at which the formation of Au droplets on the Si(111) surface occurs. URL, DOI BibTeX@article{ma15041610, author = "Jaroch, Tomasz and Zdyb, Ryszard", title = "Temperature-Dependent Growth and Evolution of Silicene on Au Ultrathin Films—LEEM and LEED Studies", journal = "Materials", volume = 15, year = 2022, month = "Feb", number = 4, article-number = 1610, url = "https://www.mdpi.com/1996-1944/15/4/1610", pubmedid = 35208150, issn = "1996-1944", abstract = "The formation and evolution of silicene on ultrathin Au films have been investigated with low energy electron microscopy and diffraction. Careful control of the annealing rate and temperature of Au films epitaxially grown on the Si(111) surface allows for the preparation of a large scale, of the order of cm2, silicene sheets. Depending on the final temperature, three stages of silicene evolution can be distinguished: (i) the growth of the low buckled phase, (ii) the formation of a layered heterostructure of the low buckled and planar phases of silicene and (iii) the gradual destruction of the silicene. Each stage is characterized by its unique surface morphology and characteristic diffraction patterns. The present study gives an overview of structures formed on the surface of ultrathin Au films and morphology changes between room temperature and the temperature at which the formation of Au droplets on the Si(111) surface occurs.", doi = "10.3390/ma15041610" }Ryszard Zdyb, Krisztián Palotás, Eszter Simon, Tomasz Jaroch and Zbigniew Korczak.
Tuning Ferromagnetism in a Single Layer of Fe above Room Temperature.
Materials 15(3), January 2022.
Abstract The crystallographic and magnetic properties of an Fe monolayer (ML) grown on 2 ML Au/W(110) substrate are studied with spin-polarized low-energy electron microscopy, density functional theory, and relativistic screened Korringa–Kohn–Rostoker calculations. The single layer of iron atoms possesses hexagonal symmetry and reveals a ferromagnetic order at room temperature. We experimentally demonstrate the possibility of tuning the Curie temperature and the magnitude of magnetization of the Fe monolayer by capping with Au. Taking into account several structural models, the calculation results mostly show ferromagnetic states with enhanced magnetic moments of Fe atoms compared to their bulk value and a further increase in their value after covering with Au. The theoretically calculated Curie temperatures are in fair agreement with those obtained in the experiments. The calculations, furthermore, found evidence for the presence of frustrated isotropic Fe–Fe exchange interactions, and a discussion of the structural effects on the magnetic properties is provided herein. URL, DOI BibTeX@article{ma15031019, author = "Zdyb, Ryszard and Palotás, Krisztián and Simon, Eszter and Jaroch, Tomasz and Korczak, Zbigniew", title = "Tuning Ferromagnetism in a Single Layer of Fe above Room Temperature", journal = "Materials", volume = 15, year = 2022, month = "Jan", number = 3, article-number = 1019, url = "https://www.mdpi.com/1996-1944/15/3/1019", issn = "1996-1944", abstract = "The crystallographic and magnetic properties of an Fe monolayer (ML) grown on 2 ML Au/W(110) substrate are studied with spin-polarized low-energy electron microscopy, density functional theory, and relativistic screened Korringa–Kohn–Rostoker calculations. The single layer of iron atoms possesses hexagonal symmetry and reveals a ferromagnetic order at room temperature. We experimentally demonstrate the possibility of tuning the Curie temperature and the magnitude of magnetization of the Fe monolayer by capping with Au. Taking into account several structural models, the calculation results mostly show ferromagnetic states with enhanced magnetic moments of Fe atoms compared to their bulk value and a further increase in their value after covering with Au. The theoretically calculated Curie temperatures are in fair agreement with those obtained in the experiments. The calculations, furthermore, found evidence for the presence of frustrated isotropic Fe–Fe exchange interactions, and a discussion of the structural effects on the magnetic properties is provided herein.", doi = "10.3390/ma15031019" }Agnieszka Stępniak-Dybala, Marek Kopciuszyński, Mieczysław Jałochowski and Mariusz Krawiec.
Coexistence of two gold-induced one-dimensional structures on a single terrace of the Si(11 11 13).
Applied Surface Science 573:151501, January 2022.
Abstract Regular arrays of silicon terraces with coexisting two gold-induced one-dimensional structures have been synthesized on the Si(11 11 13) surface. For the first time, it was possible to confine the well-known 5x2-Au reconstruction to narrow stripes separated by atomic steps and preserving its basic properties. Moreover, each terrace consists of additional chain of gold atoms that shows the same crystallographic and electronic properties to the Si(557)-Au surface. The results obtained by scanning tunneling microscopy and angle-resolved photoemission spectroscopy supplemented by first-principles density functional theory calculations allow to identify fingerprints of 5x2-Au and Si(557)-Au structures occupying the same terrace. This contrasts with the whole family of gold chains on vicinal silicon surfaces and presents new paradigm in engineering of complex one-dimensional nanostructures on stepped surfaces. URL, DOI BibTeX@article{STEPNIAKDYBALA2022151501, title = "Coexistence of two gold-induced one-dimensional structures on a single terrace of the Si(11 11 13)", journal = "Applied Surface Science", volume = 573, pages = 151501, year = 2022, month = "Jan", issn = "0169-4332", doi = "https://doi.org/10.1016/j.apsusc.2021.151501", url = "https://www.sciencedirect.com/science/article/pii/S0169433221025514", author = "Agnieszka Stępniak-Dybala and Marek Kopciuszyński and Mieczysław Jałochowski and Mariusz Krawiec", keywords = "1D nanomaterials, Vicinal, Scanning tunneling microscopy, Density functional theory, Silicon", abstract = "Regular arrays of silicon terraces with coexisting two gold-induced one-dimensional structures have been synthesized on the Si(11 11 13) surface. For the first time, it was possible to confine the well-known 5x2-Au reconstruction to narrow stripes separated by atomic steps and preserving its basic properties. Moreover, each terrace consists of additional chain of gold atoms that shows the same crystallographic and electronic properties to the Si(557)-Au surface. The results obtained by scanning tunneling microscopy and angle-resolved photoemission spectroscopy supplemented by first-principles density functional theory calculations allow to identify fingerprints of 5x2-Au and Si(557)-Au structures occupying the same terrace. This contrasts with the whole family of gold chains on vicinal silicon surfaces and presents new paradigm in engineering of complex one-dimensional nanostructures on stepped surfaces." }Marcin Kurzyna and Tomasz Kwapiński.
Braid Plot—A Mixed Palette Plotting Method as an Extension of Contour Plot.
IEEE Computer Graphics and Applications 42(1):95-104, January 2022.
Abstract n this article, we propose a new method of three-dimensional data plotting based on the use of mixed hue palettes, which makes it possible to distinguish simultaneously both huge and subtle changes in the value of the presented quantity at the same plot. This method called “braid plot” is based on the alternating use of multiple palettes of colors (a kind of interlacing), which greatly increases the sharpness of the graph and allows us to define areas of equal values more accurately than using traditional graphs with a single palette or contour plot. We present here an algorithm of preparing braid plot composed of any number of initial color sets. As a result of using this type of plot, it was possible to detect, e.g., weak perturbation effects or subtle oscillations of the spectral density function, which is very hard to observe using classical plots. DOI BibTeX@article{9351618, author = "Kurzyna, Marcin and Kwapiński, Tomasz", journal = "IEEE Computer Graphics and Applications", title = "Braid Plot—A Mixed Palette Plotting Method as an Extension of Contour Plot", year = 2022, month = "Jan", abstract = "n this article, we propose a new method of three-dimensional data plotting based on the use of mixed hue palettes, which makes it possible to distinguish simultaneously both huge and subtle changes in the value of the presented quantity at the same plot. This method called “braid plot” is based on the alternating use of multiple palettes of colors (a kind of interlacing), which greatly increases the sharpness of the graph and allows us to define areas of equal values more accurately than using traditional graphs with a single palette or contour plot. We present here an algorithm of preparing braid plot composed of any number of initial color sets. As a result of using this type of plot, it was possible to detect, e.g., weak perturbation effects or subtle oscillations of the spectral density function, which is very hard to observe using classical plots.", volume = 42, number = 1, pages = "95-104", doi = "10.1109/MCG.2021.3057924" }
2021
Mariusz Krawiec, Agnieszka Stępniak-Dybala, Andrzej Bobyk and Ryszard Zdyb.
Magnetism in Au-Supported Planar Silicene.
Nanomaterials 11(10), September 2021.
Abstract The adsorption and substitution of transition metal atoms (Fe and Co) on Au-supported planar silicene have been studied by means of first-principles density functional theory calculations. The structural, energetic and magnetic properties have been analyzed. Both dopants favor the same atomic configurations with rather strong binding energies and noticeable charge transfer. The adsorption of Fe and Co atoms do not alter the magnetic properties of Au-supported planar silicene, unless a full layer of adsorbate is completed. In the case of substituted system only Fe is able to produce magnetic ground state. The Fe-doped Au-supported planar silicene is a ferromagnetic structure with local antiferromagnetic ordering. The present study is the very first and promising attempt towards ferromagnetic epitaxial planar silicene and points to the importance of the substrate in structural and magnetic properties of silicene. URL, DOI BibTeX@article{nano11102568, author = "Krawiec, Mariusz and Stępniak-Dybala, Agnieszka and Bobyk, Andrzej and Zdyb, Ryszard", title = "Magnetism in Au-Supported Planar Silicene", journal = "Nanomaterials", volume = 11, year = 2021, month = "Sep", number = 10, article-number = 2568, url = "https://www.mdpi.com/2079-4991/11/10/2568", pubmedid = 34685008, issn = "2079-4991", abstract = "The adsorption and substitution of transition metal atoms (Fe and Co) on Au-supported planar silicene have been studied by means of first-principles density functional theory calculations. The structural, energetic and magnetic properties have been analyzed. Both dopants favor the same atomic configurations with rather strong binding energies and noticeable charge transfer. The adsorption of Fe and Co atoms do not alter the magnetic properties of Au-supported planar silicene, unless a full layer of adsorbate is completed. In the case of substituted system only Fe is able to produce magnetic ground state. The Fe-doped Au-supported planar silicene is a ferromagnetic structure with local antiferromagnetic ordering. The present study is the very first and promising attempt towards ferromagnetic epitaxial planar silicene and points to the importance of the substrate in structural and magnetic properties of silicene.", doi = "10.3390/nano11102568" }Marek Dachniewicz, Marek Kopciuszyński, Lucyna Żurawek, Mirosław Strȯżak, Mariusz Krawiec and Mieczysław Jałochowski.
Evidence for Electronically Isolated Atomic Chains: Sb–Pb Structures on the Si(553) Surface.
The Journal of Physical Chemistry C 125(27):15061, June 2021.
Abstract Metallic atomic chains weakly coupled to the substrate may be a practical implementation of extreme one-dimensional quantum systems. We report a two-step method of assembling one-dimensional Sb atomic chains on an ordered stepped Si(553) surface with Pb nanoribbons. We show that Pb atoms act as a surfactant, induce the dissociation of Sb molecules, and enable the formation of monatomic chains. Combining atomistic modeling within density functional theory with scanning tunneling microscopy and angle-resolved photoemission spectroscopy, we demonstrate that the formed Sb chains are highly strained and at the same time electronically isolated, exhibiting extremely well-defined one-dimensional free-electron like behavior. URL, DOI BibTeX@article{doi:10.1021/acs.jpcc.1c03983, author = "Dachniewicz, Marek and Kopciuszyński, Marek and Żurawek, Lucyna and Strȯżak, Mirosław and Krawiec, Mariusz and Jałochowski, Mieczysław", title = "Evidence for Electronically Isolated Atomic Chains: Sb–Pb Structures on the Si(553) Surface", journal = "The Journal of Physical Chemistry C", volume = 125, number = 27, pages = 15061, year = 2021, month = "Jun", doi = "10.1021/acs.jpcc.1c03983", url = "https://doi.org/10.1021/acs.jpcc.1c03983", eprint = "https://doi.org/10.1021/acs.jpcc.1c03983", abstract = "Metallic atomic chains weakly coupled to the substrate may be a practical implementation of extreme one-dimensional quantum systems. We report a two-step method of assembling one-dimensional Sb atomic chains on an ordered stepped Si(553) surface with Pb nanoribbons. We show that Pb atoms act as a surfactant, induce the dissociation of Sb molecules, and enable the formation of monatomic chains. Combining atomistic modeling within density functional theory with scanning tunneling microscopy and angle-resolved photoemission spectroscopy, we demonstrate that the formed Sb chains are highly strained and at the same time electronically isolated, exhibiting extremely well-defined one-dimensional free-electron like behavior." }Tomasz Kwapiński and Marcin Kurzyna.
Topological Atomic Chains on 2D Hybrid Structure.
Materials 14(12), June 2021.
Abstract Mid-gap 1D topological states and their electronic properties on different 2D hybrid structures are investigated using the tight binding Hamiltonian and the Green’s function technique. There are considered straight armchair-edge and zig-zag Su–Schrieffer–Heeger (SSH) chains coupled with real 2D electrodes which density of states (DOS) are characterized by the van Hove singularities. In this work, it is shown that such 2D substrates substantially influence topological states end evoke strong asymmetry in their on-site energetic structures, as well as essential modifications of the spectral density function (local DOS) along the chain. In the presence of the surface singularities the SSH topological state is split, or it is strongly localized and becomes dispersionless (tends to the atomic limit). Additionally, in the vicinity of the surface DOS edges this state is asymmetrical and consists of a wide bulk part together with a sharp localized peak in its local DOS structure. Different zig-zag and armachair-edge configurations of the chain show the spatial asymmetry in the chain local DOS; thus, topological edge states at both chain ends can appear for different energies. These new effects cannot be observed for ideal wide band limit electrodes but they concern 1D topological states coupled with real 2D hybrid structures. URL, DOI BibTeX@article{ma14123289, author = "Kwapiński, Tomasz and Kurzyna, Marcin", title = "Topological Atomic Chains on 2D Hybrid Structure", journal = "Materials", volume = 14, year = 2021, month = "Jun", number = 12, article-number = 3289, url = "https://www.mdpi.com/1996-1944/14/12/3289", pubmedid = 34198678, issn = "1996-1944", abstract = "Mid-gap 1D topological states and their electronic properties on different 2D hybrid structures are investigated using the tight binding Hamiltonian and the Green’s function technique. There are considered straight armchair-edge and zig-zag Su–Schrieffer–Heeger (SSH) chains coupled with real 2D electrodes which density of states (DOS) are characterized by the van Hove singularities. In this work, it is shown that such 2D substrates substantially influence topological states end evoke strong asymmetry in their on-site energetic structures, as well as essential modifications of the spectral density function (local DOS) along the chain. In the presence of the surface singularities the SSH topological state is split, or it is strongly localized and becomes dispersionless (tends to the atomic limit). Additionally, in the vicinity of the surface DOS edges this state is asymmetrical and consists of a wide bulk part together with a sharp localized peak in its local DOS structure. Different zig-zag and armachair-edge configurations of the chain show the spatial asymmetry in the chain local DOS; thus, topological edge states at both chain ends can appear for different energies. These new effects cannot be observed for ideal wide band limit electrodes but they concern 1D topological states coupled with real 2D hybrid structures.", doi = "10.3390/ma14123289" }Tomasz Jaroch, Mariusz Krawiec and Ryszard Zdyb.
Layered heterostructure of planar and buckled phases of silicene.
2D Materials 8(3):035038, May 2021.
Abstract Heterostructures made of two-dimensional (2D) materials became a topic of numerous studies due to their new and often unexpected properties. Typically, in such systems 2D structures are composed of various elements. Here, a heterostructure made of different phases of the same material is presented. Layered planar and buckled phases of silicene are prepared in a self-organization process during annealing of ultrathin layers of Au grown on Si(111) surface. Low energy electron microscopy studies show that both phases form continuous parallel layers which are twisted in respect to each other and which cover entire surface of the Au film making an ordered sheet of a size of cm2. Such heterostructures might be important for the development of new electronic and optoelectronic devices. URL, DOI BibTeX@article{Jaroch_2021, doi = "10.1088/2053-1583/ac00fb", url = "https://doi.org/10.1088/2053-1583/ac00fb", year = 2021, month = "May", publisher = "{IOP} Publishing", volume = 8, number = 3, pages = 035038, author = "Tomasz Jaroch and Mariusz Krawiec and Ryszard Zdyb", title = "Layered heterostructure of planar and buckled phases of silicene", journal = "2D Materials", abstract = "Heterostructures made of two-dimensional (2D) materials became a topic of numerous studies due to their new and often unexpected properties. Typically, in such systems 2D structures are composed of various elements. Here, a heterostructure made of different phases of the same material is presented. Layered planar and buckled phases of silicene are prepared in a self-organization process during annealing of ultrathin layers of Au grown on Si(111) surface. Low energy electron microscopy studies show that both phases form continuous parallel layers which are twisted in respect to each other and which cover entire surface of the Au film making an ordered sheet of a size of cm2. Such heterostructures might be important for the development of new electronic and optoelectronic devices." }Andrzej Daniluk, Lucyna Żurawek and Ryszard Zdyb.
An effective method to calculate RHEED rocking curves from nanoheteroepitaxial systems.
Computer Physics Communications 261:107692, April 2021.
Abstract We report a simulation program which facilitates the calculation of changes in the intensity of specular reflection of electron beams in RHEED experiments for thin epitaxial films deposited on crystalline surfaces. It has been shown that the amplitude of the RHEED intensity oscillations greatly depends on the glancing angle of the incident electron beam, the coverages of the growing layers and the model of the scattering potential. The usefulness of the program has been tested on a well-known system of Ag grown on a Si(111) surface. The obtained experimental and computational results correspond closely. The presented algorithm, together with properly modified input data, can be applied to other systems of crystalline ultrathin layer and substrate. It also enables the implementation and tests of different combinations of the scattering potentials of the crystal, and can be applied to interpret experimental RHEED rocking curves. URL, DOI BibTeX@article{DANILUK2021107692, title = "An effective method to calculate RHEED rocking curves from nanoheteroepitaxial systems", journal = "Computer Physics Communications", volume = 261, pages = 107692, year = 2021, month = "Apr", issn = "0010-4655", doi = "https://doi.org/10.1016/j.cpc.2020.107692", url = "https://www.sciencedirect.com/science/article/pii/S0010465520303404", author = "Andrzej Daniluk and Lucyna Żurawek and Ryszard Zdyb", keywords = "Scientific computing, Numerical simulations, Diffuse scattering, RHEED, MBE", abstract = "We report a simulation program which facilitates the calculation of changes in the intensity of specular reflection of electron beams in RHEED experiments for thin epitaxial films deposited on crystalline surfaces. It has been shown that the amplitude of the RHEED intensity oscillations greatly depends on the glancing angle of the incident electron beam, the coverages of the growing layers and the model of the scattering potential. The usefulness of the program has been tested on a well-known system of Ag grown on a Si(111) surface. The obtained experimental and computational results correspond closely. The presented algorithm, together with properly modified input data, can be applied to other systems of crystalline ultrathin layer and substrate. It also enables the implementation and tests of different combinations of the scattering potentials of the crystal, and can be applied to interpret experimental RHEED rocking curves." }Juan Jose Gutierrez-Sevillano, Agata Podsiadły-Paszkowska, Bartłomiej M Szyja and Sofia Calero.
On the design of models for an accurate description of the water – hematite interface.
Applied Surface Science 560:149884, April 2021.
Abstract In this work we use classical methods to develop an accurate model able to describe the interactions between the molecule of water and the hematite surface. We study the variation of the interaction energy between the water molecule and the surface regarding some geometrical aspects such as the proximity to different parts of the surface, the molecule-surface distance, and the orientation of the molecule. We obtain energy profiles and compare them with results obtained using DFT. In the study we use polarizable and non-polarizable models to find out the best balance between simple and fast models, and accurate results. We found that our developed point charges model reproduces the DFT results better than a core shell model. The obtained force field parameters will make it possible to accelerate the research on the iron oxides and water interfaces used in the description of the water-splitting reaction, which is a low-emission hydrogen source. URL, DOI BibTeX@article{GUTIERREZSEVILLANO2021149884, title = "On the design of models for an accurate description of the water – hematite interface", journal = "Applied Surface Science", volume = 560, pages = 149884, year = 2021, month = "Apr", issn = "0169-4332", doi = "https://doi.org/10.1016/j.apsusc.2021.149884", url = "https://www.sciencedirect.com/science/article/pii/S0169433221009600", author = "Juan Jose Gutierrez-Sevillano and Agata Podsiadły-Paszkowska and Bartłomiej M. Szyja and Sofia Calero", keywords = "Water splitting, DFT, Substitutions, Catalyst", abstract = "In this work we use classical methods to develop an accurate model able to describe the interactions between the molecule of water and the hematite surface. We study the variation of the interaction energy between the water molecule and the surface regarding some geometrical aspects such as the proximity to different parts of the surface, the molecule-surface distance, and the orientation of the molecule. We obtain energy profiles and compare them with results obtained using DFT. In the study we use polarizable and non-polarizable models to find out the best balance between simple and fast models, and accurate results. We found that our developed point charges model reproduces the DFT results better than a core shell model. The obtained force field parameters will make it possible to accelerate the research on the iron oxides and water interfaces used in the description of the water-splitting reaction, which is a low-emission hydrogen source." }Mateusz Wróbel, Tomasz Żaba, Eric Sauter, Mariusz Krawiec, Joanna Sobczuk, Andreas Terfort, Michael Zharnikov and Piotr Cyganik.
Thermally Stable and Highly Conductive SAMs on Ag Substrate—The Impact of the Anchoring Group.
Advanced Electronic Materials 7(2):2000947, February 2021.
Abstract Abstract Self-assembled monolayers (SAMs) on metal substrates are an important part of modern interfacial chemistry and nanotechnology. The robustness of SAMs strongly depends on their thermal stability, which, together with electric conductivity, crucial for their applications in molecular/organic electronics. In this context, using a multidisciplinary approach, the structure, stability, and conductivity properties of conjugated aromatic SAMs featuring the naphthalene backbone and S, Se, or COO group, mediating bonding to the Ag substrate are addressed. Whereas thermal stability of these SAMs exhibits a strong dependence on anchoring group, their conductivity is similar, which is rationalized by tentative model considering redistribution of charge density along the molecular framework. The thermal stability of model naphthalenethiol SAM, emphasized by desorption energy of ≈1.69 eV, is better than that of typical N-heterocyclic carbene (NHC) monolayers considered currently as the most stable SAMs on metal substrates. However, in contrast to NHC SAMs, which are highly insulating, the naphtalene-based SAM, with S, Se or COO anchoring groups, are highly conductive, even in comparison with analogous oligophenyl SAMs (by a factor of 10). A unique combination of the ultimate thermal stability and superior conductivity for the naphthalenethiol SAM on Ag makes it highly attractive for applications. URL, DOI BibTeX@article{https://doi.org/10.1002/aelm.202000947, author = "Wróbel, Mateusz and Żaba, Tomasz and Sauter, Eric and Krawiec, Mariusz and Sobczuk, Joanna and Terfort, Andreas and Zharnikov, Michael and Cyganik, Piotr", title = "Thermally Stable and Highly Conductive SAMs on Ag Substrate—The Impact of the Anchoring Group", journal = "Advanced Electronic Materials", volume = 7, number = 2, pages = 2000947, keywords = "conductivity, interface engineering, molecular electronics, self-assembled monolayers, thermal stability", doi = "https://doi.org/10.1002/aelm.202000947", url = "https://onlinelibrary.wiley.com/doi/abs/10.1002/aelm.202000947", eprint = "https://onlinelibrary.wiley.com/doi/pdf/10.1002/aelm.202000947", abstract = "Abstract Self-assembled monolayers (SAMs) on metal substrates are an important part of modern interfacial chemistry and nanotechnology. The robustness of SAMs strongly depends on their thermal stability, which, together with electric conductivity, crucial for their applications in molecular/organic electronics. In this context, using a multidisciplinary approach, the structure, stability, and conductivity properties of conjugated aromatic SAMs featuring the naphthalene backbone and S, Se, or COO group, mediating bonding to the Ag substrate are addressed. Whereas thermal stability of these SAMs exhibits a strong dependence on anchoring group, their conductivity is similar, which is rationalized by tentative model considering redistribution of charge density along the molecular framework. The thermal stability of model naphthalenethiol SAM, emphasized by desorption energy of ≈1.69 eV, is better than that of typical N-heterocyclic carbene (NHC) monolayers considered currently as the most stable SAMs on metal substrates. However, in contrast to NHC SAMs, which are highly insulating, the naphtalene-based SAM, with S, Se or COO anchoring groups, are highly conductive, even in comparison with analogous oligophenyl SAMs (by a factor of 10). A unique combination of the ultimate thermal stability and superior conductivity for the naphthalenethiol SAM on Ag makes it highly attractive for applications.", month = "Feb", year = 2021 }Marcin Kurzyna and Tomasz Kwapiński.
Electron Pumping and Spectral Density Dynamics in Energy-Gapped Topological Chains.
Applied Sciences 11(2), January 2021.
Abstract Electron pumping through energy-gapped systems is restricted for vanishing local density of states at the Fermi level. In this paper, we propose a topological Su–Schrieffer–Heeger (SSH) chain between unbiased leads as an effective electron pump. We analyze the electron transport properties of topologically trivial and nontrivial systems in the presence of external time-dependent forces in the form of one-Gaussian or two-Gaussian perturbations (train impulses). We have found that the topologically trivial chain stands for much better charge pump than other normal or nontrivial chains. It is important that, during the perturbation, electrons are pumped through the mid-gap temporary states or through the induced sidebands states outside the energy gap. We also analyze the local density of states dynamics during the quench transition between different topological phases of the SSH chain. It turns out that after the quench, the edge topological states migrate through other sites and can temporarily exist in a topologically trivial part of the system. The tight-binding Hamiltonian and the evolution operator technique are used in our calculations. URL, DOI BibTeX@article{app11020772, author = "Kurzyna, Marcin and Kwapiński, Tomasz", title = "Electron Pumping and Spectral Density Dynamics in Energy-Gapped Topological Chains", journal = "Applied Sciences", volume = 11, year = 2021, month = "Jan", number = 2, article-number = 772, url = "https://www.mdpi.com/2076-3417/11/2/772", issn = "2076-3417", abstract = "Electron pumping through energy-gapped systems is restricted for vanishing local density of states at the Fermi level. In this paper, we propose a topological Su–Schrieffer–Heeger (SSH) chain between unbiased leads as an effective electron pump. We analyze the electron transport properties of topologically trivial and nontrivial systems in the presence of external time-dependent forces in the form of one-Gaussian or two-Gaussian perturbations (train impulses). We have found that the topologically trivial chain stands for much better charge pump than other normal or nontrivial chains. It is important that, during the perturbation, electrons are pumped through the mid-gap temporary states or through the induced sidebands states outside the energy gap. We also analyze the local density of states dynamics during the quench transition between different topological phases of the SSH chain. It turns out that after the quench, the edge topological states migrate through other sites and can temporarily exist in a topologically trivial part of the system. The tight-binding Hamiltonian and the evolution operator technique are used in our calculations.", doi = "10.3390/app11020772" }
2020
M Kurzyna and T Kwapiński.
Nontrivial dynamics of a two-site system: Transient crystals.
Phys. Rev. B 102:245414, December 2020.
Abstract We analyze theoretically quench dynamics of a two-site system abruptly driven from its equilibrium state focusing on the time dependent spectral density function. In the presence of electron reservoirs this function reveals in time a nontrivial regular pattern of peaks corresponding to the stationary quantum chain structure. Such dynamical system with periodic structure of the spectral density stands for a new transient crystal material. We investigate here the role of the Coulomb repulsion between the sites, nontrivial substrates and different system geometries on the transient crystal pattern which can be measured in the tunneling conductance experiments. We also propose the transient crystal system between unbiased leads as an effective monoparametric pump. URL, DOI BibTeX@article{PhysRevB.102.245414, title = "Nontrivial dynamics of a two-site system: Transient crystals", author = "Kurzyna, M. and Kwapiński, T.", abstract = "We analyze theoretically quench dynamics of a two-site system abruptly driven from its equilibrium state focusing on the time dependent spectral density function. In the presence of electron reservoirs this function reveals in time a nontrivial regular pattern of peaks corresponding to the stationary quantum chain structure. Such dynamical system with periodic structure of the spectral density stands for a new transient crystal material. We investigate here the role of the Coulomb repulsion between the sites, nontrivial substrates and different system geometries on the transient crystal pattern which can be measured in the tunneling conductance experiments. We also propose the transient crystal system between unbiased leads as an effective monoparametric pump.", journal = "Phys. Rev. B", volume = 102, issue = 24, pages = 245414, numpages = 10, year = 2020, month = "Dec", publisher = "American Physical Society", doi = "10.1103/PhysRevB.102.245414", url = "https://link.aps.org/doi/10.1103/PhysRevB.102.245414" }M Kurzyna and T Kwapiński.
Edge-state dynamics in coupled topological chains.
Phys. Rev. B 102:195429, November 2020.
Abstract We study time-dependent electrical properties of the Su-Schrieffer-Heeger (SSH) chain and coupled SSH chains on a substrate. Focusing on the midgap edge state dynamics we consider the abrupt transition from the normal to the SSH chain and determine characteristic timescale needed for topological states to develop. We have found that the midgap state is formed from the inside peaks of the normal chain density of states. For a ladderlike system we show that the edge SSH state vanishes in time or oscillates between neighboring sites. Moreover, for nonadiabatical time-dependent perturbations the midgap state can partially leak to other sites leading to induced topological states inside the trivial chain. We also analyze the mean-field correlation effects between the coupled chains revealing the induced Friedel oscillations in nontrivial chains. URL, DOI BibTeX@article{PhysRevB.102.195429, title = "Edge-state dynamics in coupled topological chains", author = "Kurzyna, M. and Kwapiński, T.", abstract = "We study time-dependent electrical properties of the Su-Schrieffer-Heeger (SSH) chain and coupled SSH chains on a substrate. Focusing on the midgap edge state dynamics we consider the abrupt transition from the normal to the SSH chain and determine characteristic timescale needed for topological states to develop. We have found that the midgap state is formed from the inside peaks of the normal chain density of states. For a ladderlike system we show that the edge SSH state vanishes in time or oscillates between neighboring sites. Moreover, for nonadiabatical time-dependent perturbations the midgap state can partially leak to other sites leading to induced topological states inside the trivial chain. We also analyze the mean-field correlation effects between the coupled chains revealing the induced Friedel oscillations in nontrivial chains.", journal = "Phys. Rev. B", volume = 102, issue = 19, pages = 195429, numpages = 14, year = 2020, month = "Nov", publisher = "American Physical Society", doi = "10.1103/PhysRevB.102.195429", url = "https://link.aps.org/doi/10.1103/PhysRevB.102.195429" }M Kopciuszyński, A Stȩpniak-Dybala, M Dachniewicz, L Żurawek, M Krawiec and R Zdyb.
Hut-shaped lead nanowires with one-dimensional electronic properties.
Physical Review B 102(12), September 2020.
Abstract The ultrathin Pb layer on the Si(110) surface might be converted into hut-shaped nanowires extending in a unique [-110] direction. Despite the fact that about 2.6 ML of lead is used to form an ordered array of nanowires, this system shows not only anisotropy of the electronic structure but also a small band gap in the [001] direction. Among several quasi-one-dimensional bands, two of them show pure one-dimensional character. Electron dispersion maps measured with photoelectron spectroscopy are supported by scanning tunneling spectroscopy data which confirm the absence of electronic states at the Fermi level in areas between lead nanowires. Based on first-principles density functional theory calculations four different structural models of lead nanowires are proposed reflecting a different number of Pb atoms in the unit cell. DOI BibTeX@article{Kop20, abstract = "The ultrathin Pb layer on the Si(110) surface might be converted into hut-shaped nanowires extending in a unique [-110] direction. Despite the fact that about 2.6 ML of lead is used to form an ordered array of nanowires, this system shows not only anisotropy of the electronic structure but also a small band gap in the [001] direction. Among several quasi-one-dimensional bands, two of them show pure one-dimensional character. Electron dispersion maps measured with photoelectron spectroscopy are supported by scanning tunneling spectroscopy data which confirm the absence of electronic states at the Fermi level in areas between lead nanowires. Based on first-principles density functional theory calculations four different structural models of lead nanowires are proposed reflecting a different number of Pb atoms in the unit cell.", author = "Kopciuszyński, M. and Stȩpniak-Dybala, A. and Dachniewicz, M. and Żurawek, L. and Krawiec, M. and Zdyb, R.", doi = "10.1103/physrevb.102.125415", issn = "2469-9969", journal = "Physical Review B", month = "Sep", number = 12, publisher = "American Physical Society (APS)", title = "Hut-shaped lead nanowires with one-dimensional electronic properties", volume = 102, x-fetchedfrom = "DOI", year = 2020 }L Żurawek, M Kopciuszyński, M Dachniewicz, M Stróżak, M Krawiec, M Jałochowski and R Zdyb.
Partially embedded Pb chains on a vicinal Si(113) surface.
Physical Review B 101(19), May 2020.
Abstract Partially embedded Pb chains are synthesized on a vicinal Si(113) surface in a process of self-organization. The deposition of one monolayer-range amount of Pb orders the substrate over the macroscopic scale and results in extremely long monatomic chains reproducing Si lattice geometry, as demonstrated by reflection high-energy electron diffraction and scanning tunneling microscopy. Angle-resolved photoelectron spectroscopy reveals well-developed one-dimensional metallic bands. Ab initio density functional theory calculations fully support the experimental findings and predict partially embedded zigzag Pb chains with substantially spin-orbit-split one-dimensional electron bands. The present work is experimental evidence of a new type of one-dimensional structures in which one of two chains of atoms building the structure is embedded in the substrate. URL, DOI BibTeX@article{Zur20, abstract = "Partially embedded Pb chains are synthesized on a vicinal Si(113) surface in a process of self-organization. The deposition of one monolayer-range amount of Pb orders the substrate over the macroscopic scale and results in extremely long monatomic chains reproducing Si lattice geometry, as demonstrated by reflection high-energy electron diffraction and scanning tunneling microscopy. Angle-resolved photoelectron spectroscopy reveals well-developed one-dimensional metallic bands. Ab initio density functional theory calculations fully support the experimental findings and predict partially embedded zigzag Pb chains with substantially spin-orbit-split one-dimensional electron bands. The present work is experimental evidence of a new type of one-dimensional structures in which one of two chains of atoms building the structure is embedded in the substrate.", author = "Żurawek, L. and Kopciuszyński, M. and Dachniewicz, M. and Stróżak, M. and Krawiec, M. and Jałochowski, M. and Zdyb, R.", doi = "10.1103/physrevb.101.195434", issn = "2469-9969", journal = "Physical Review B", month = "May", number = 19, page = 195434, publisher = "American Physical Society (APS)", title = "Partially embedded Pb chains on a vicinal Si(113) surface", url = "http://dx.doi.org/10.1103/PhysRevB.101.195434", volume = 101, x-fetchedfrom = "DOI", year = 2020 }Wojciech Belza, Konrad Szajna, Markus Kratzer, Dominik Wrana, Karol Cieslik, Mariusz Krawiec, Christian Teichert and Franciszek Krok.
Molecular Structure and Electronic Properties of para-Hexaphenyl Monolayer on Atomically Flat Rutile TiO2(110).
The Journal of Physical Chemistry C 124(10):5681–5689, February 2020.
Abstract The structure and stability of a molecular wetting layer of the rodlike organic semiconductor molecule para-hexaphenyl grown at room temperature on atomically flat titanium dioxide TiO2(110) surfaces are investigated. The inner structure of the wetting layer was imaged with molecular resolution by means of scanning tunneling microscopy. The formation of molecular stripes with a molecular tilt of the alternating molecules is found, which is also confirmed by low-energy electron diffraction measurements and density functional theory (DFT) calculations. In the wetting layer, the molecular short axes are tilted by 20° with respect to the substrate surface plane. At submonolayer coverages, the molecules are highly mobile but finally form a compact and stable monomolecular wetting layer. Such a complete monolayer can be a precursor for the growth of crystalline para-hexaphenyl molecular nanoneedles. DFT calculations yielded adsorption energies of EdesWL = 4.06 eV/molecule for the wetting layer and EdesN = 2.71 eV/molecule for the nanoneedles, which is in fairly good agreement with molecular desorption energies deduced from thermal desorption spectroscopy (EdesWL = 3.75 ± 0.41 eV for the wetting layer and EdesN = 2.27 ± 0.26 eV for the nanoneedles). DFT also revealed charge transfer from 6P to TiO2 of 0.26 e/molecule, accompanied by a change in work function, which is in qualitative agreement with Kelvin probe force microscopy measurements. DOI BibTeX@article{Bel20, abstract = "The structure and stability of a molecular wetting layer of the rodlike organic semiconductor molecule para-hexaphenyl grown at room temperature on atomically flat titanium dioxide TiO2(110) surfaces are investigated. The inner structure of the wetting layer was imaged with molecular resolution by means of scanning tunneling microscopy. The formation of molecular stripes with a molecular tilt of the alternating molecules is found, which is also confirmed by low-energy electron diffraction measurements and density functional theory (DFT) calculations. In the wetting layer, the molecular short axes are tilted by 20° with respect to the substrate surface plane. At submonolayer coverages, the molecules are highly mobile but finally form a compact and stable monomolecular wetting layer. Such a complete monolayer can be a precursor for the growth of crystalline para-hexaphenyl molecular nanoneedles. DFT calculations yielded adsorption energies of EdesWL = 4.06 eV/molecule for the wetting layer and EdesN = 2.71 eV/molecule for the nanoneedles, which is in fairly good agreement with molecular desorption energies deduced from thermal desorption spectroscopy (EdesWL = 3.75 ± 0.41 eV for the wetting layer and EdesN = 2.27 ± 0.26 eV for the nanoneedles). DFT also revealed charge transfer from 6P to TiO2 of 0.26 e/molecule, accompanied by a change in work function, which is in qualitative agreement with Kelvin probe force microscopy measurements.", author = "Belza, Wojciech and Szajna, Konrad and Kratzer, Markus and Wrana, Dominik and Cieslik, Karol and Krawiec, Mariusz and Teichert, Christian and Krok, Franciszek", doi = "10.1021/acs.jpcc.9b11533", issn = "1932-7455", journal = "The Journal of Physical Chemistry C", month = "Feb", number = 10, pages = "5681–5689", publisher = "American Chemical Society (ACS)", title = "Molecular Structure and Electronic Properties of para-Hexaphenyl Monolayer on Atomically Flat Rutile TiO2(110)", volume = 124, x-fetchedfrom = "DOI", year = 2020 }Marek Kopciuszyński, Mariusz Krawiec, Lucyna Żurawek and Ryszard Zdyb.
Experimental evidence of a new class of massless fermions.
Nanoscale Horiz. 5:679–682, 2020.
Abstract The discovery of graphene with its massless fermions established a new branch of nanomaterials in which linear bands can be realized. It has been predicted that beside Dirac fermions revealing isotropic character and observed in a number of two-dimensional materials, another class of massless fermions can also be found: strongly anisotropic fortune teller-like states which form planes instead of cones in the electronic structure. Here, we demonstrate that such distinct electronic structures exist and can be found in a surface layer of silicon. URL, DOI BibTeX@article{C9NH00681H, abstract = "The discovery of graphene with its massless fermions established a new branch of nanomaterials in which linear bands can be realized. It has been predicted that beside Dirac fermions revealing isotropic character and observed in a number of two-dimensional materials{,} another class of massless fermions can also be found: strongly anisotropic fortune teller-like states which form planes instead of cones in the electronic structure. Here{,} we demonstrate that such distinct electronic structures exist and can be found in a surface layer of silicon.", author = "Kopciuszyński, Marek and Krawiec, Mariusz and Żurawek, Lucyna and Zdyb, Ryszard", doi = "10.1039/C9NH00681H", issue = 4, journal = "Nanoscale Horiz.", pages = "679–682", publisher = "The Royal Society of Chemistry", title = "Experimental evidence of a new class of massless fermions", url = "http://dx.doi.org/10.1039/C9NH00681H", volume = 5, year = 2020 }
2019
T Jaroch, S Chen, R Zdyb, M Jałochowski, P A Thiel and M C Tringides.
Non-classical nucleation and collective diffusion in epitaxially grown ultrathin films.
Journal of Crystal Growth 523:125137, October 2019.
Abstract Nucleation phenomena are very important in nature because they control the formation of novel phases which can have technologically important properties and applications. LEEM experiments in real time are described for island nucleation in Pb/Si(1 1 1), that show unusually fast, defect-free large Pb islands. The experiments confirm that this growth is due to the collective motion of the wetting layer and provide real time information about the rate of mass transport. Review of other experimental systems where similar unusually fast nucleation processes are present can lead to a better understanding of these intriguing processes, so predictability of the growth conditions (temperature, flux rate, coverage) can be attained. URL, DOI BibTeX@article{JAROCH2019125137, title = "Non-classical nucleation and collective diffusion in epitaxially grown ultrathin films", journal = "Journal of Crystal Growth", volume = 523, pages = 125137, year = 2019, month = "Oct", issn = "0022-0248", doi = "https://doi.org/10.1016/j.jcrysgro.2019.06.023", url = "http://www.sciencedirect.com/science/article/pii/S0022024819303446", author = "T. Jaroch and S. Chen and R. Zdyb and M. Jałochowski and P.A. Thiel and M.C. Tringides", keywords = "A1 Nucleation, A1 Diffusion, A1 Surface, A1 Low dimensional structures, A3 Molecular beam epitaxy, B1 Nanomaterials", abstract = "Nucleation phenomena are very important in nature because they control the formation of novel phases which can have technologically important properties and applications. LEEM experiments in real time are described for island nucleation in Pb/Si(1 1 1), that show unusually fast, defect-free large Pb islands. The experiments confirm that this growth is due to the collective motion of the wetting layer and provide real time information about the rate of mass transport. Review of other experimental systems where similar unusually fast nucleation processes are present can lead to a better understanding of these intriguing processes, so predictability of the growth conditions (temperature, flux rate, coverage) can be attained." }Agnieszka Stpniak-Dybala, Paweł Dyniec, Marek Kopciuszyski, Ryszard Zdyb, Mieczysław Jałochowski and Mariusz Krawiec.
Planar Silicene: A New Silicon Allotrope Epitaxially Grown by Segregation.
Advanced Functional Materials 2019:1906053, October 2019.
Abstract Abstract 2D sheets of graphene-like silicon, namely planar silicene, are synthesized. This new silicon allotrope is prepared on Au(111) thin films grown on a Si(111) substrate in the process of surface segregation. Owing to its almost perfectly flat geometry it shares the atomic structure with graphene rather than with low-buckled silicene. Scanning tunneling microscopy measurements clearly display an atomically resolved planar silicene honeycomb lattice. Ab initio density functional theory calculations fully support the experimental findings and predict a pure sp2 atomic configuration of Si atoms. The present work is the first experimental evidence of epitaxial planar silicene. URL, DOI BibTeX@article{doi:10.1002/adfm.201906053, author = "Stpniak-Dybala, Agnieszka and Dyniec, Paweł and Kopciuszyski, Marek and Zdyb, Ryszard and Jałochowski, Mieczysław and Krawiec, Mariusz", title = "Planar Silicene: A New Silicon Allotrope Epitaxially Grown by Segregation", journal = "Advanced Functional Materials", volume = 2019, pages = 1906053, year = 2019, month = "Oct", keywords = "first-principles calculations, gold, planar silicene, scanning tunneling microscopy, 2D materials", doi = "10.1002/adfm.201906053", url = "https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.201906053", eprint = "https://onlinelibrary.wiley.com/doi/pdf/10.1002/adfm.201906053", abstract = "Abstract 2D sheets of graphene-like silicon, namely planar silicene, are synthesized. This new silicon allotrope is prepared on Au(111) thin films grown on a Si(111) substrate in the process of surface segregation. Owing to its almost perfectly flat geometry it shares the atomic structure with graphene rather than with low-buckled silicene. Scanning tunneling microscopy measurements clearly display an atomically resolved planar silicene honeycomb lattice. Ab initio density functional theory calculations fully support the experimental findings and predict a pure sp2 atomic configuration of Si atoms. The present work is the first experimental evidence of epitaxial planar silicene." }M Jałochowski and M Krawiec.
Antimonene on Pb quantum wells.
2D Materials 6:045028, August 2019.
Abstract Two-dimensional sheets of hexagonal (beta—form) antimonene have been epitaxially prepared on Pb(111) ultrathin films (quantum wells) grown on Si(111)(6x6)Au. Scanning tunneling microscopy reveals two different moiré structures with wavelength of 2.3 nm and 3.8 nm on antimonene-covered surface. Ab initio density functional theory predicts the antimonene-substrate separation of 0.37 nm, that classifies this system as a van der Waals heterostructure. Despite such large separation, scanning tunneling spectroscopy evidences quantum well states in the antimonene layer too. A method of engineering of antimonene electronic band structure by means of quantum size effect has been proposed. The present work is the first experimental realization of —antimonene on metallic quantum well. URL, DOI BibTeX@article{Ja_ochowski_2019, doi = "10.1088/2053-1583/ab33ba", url = "https://doi.org/10.1088%2F2053-1583%2Fab33ba", year = 2019, month = "aug", volume = 6, pages = 045028, author = "M Jałochowski and M Krawiec", title = "Antimonene on Pb quantum wells", journal = "2D Materials", abstract = "Two-dimensional sheets of hexagonal (beta—form) antimonene have been epitaxially prepared on Pb(111) ultrathin films (quantum wells) grown on Si(111)(6x6)Au. Scanning tunneling microscopy reveals two different moiré structures with wavelength of 2.3 nm and 3.8 nm on antimonene-covered surface. Ab initio density functional theory predicts the antimonene-substrate separation of 0.37 nm, that classifies this system as a van der Waals heterostructure. Despite such large separation, scanning tunneling spectroscopy evidences quantum well states in the antimonene layer too. A method of engineering of antimonene electronic band structure by means of quantum size effect has been proposed. The present work is the first experimental realization of —antimonene on metallic quantum well." }Mateusz Wróbel, Jakub Ossowski, Mariusz Krawiec, Krzysztof Kozieł, Paweł Dąbczyński and Piotr Cyganik.
Oscillation in the stability of consecutive chemical bonds at the molecule–metal interface – the case of ionic bonding.
Phys. Chem. Chem. Phys. 21:13411, July 2019.
Abstract Ion-induced desorption was successfully applied for the analysis of the stability of chemical bonds at the molecule–metal interface in the case of ionic bonding. The obtained experimental data combined with the results of the DFT calculations reveal the effect of positional oscillations in the stability of consecutive chemical bonds, which has general character in chemistry. URL, DOI BibTeX@article{C9CP02061F, author = "Wróbel, Mateusz and Ossowski, Jakub and Krawiec, Mariusz and Kozieł, Krzysztof and Dąbczyński, Paweł and Cyganik, Piotr", title = "Oscillation in the stability of consecutive chemical bonds at the molecule–metal interface – the case of ionic bonding", journal = "Phys. Chem. Chem. Phys.", year = 2019, month = "Jul", volume = 21, issue = 25, pages = 13411, publisher = "The Royal Society of Chemistry", doi = "10.1039/C9CP02061F", url = "http://dx.doi.org/10.1039/C9CP02061F", abstract = "Ion-induced desorption was successfully applied for the analysis of the stability of chemical bonds at the molecule–metal interface in the case of ionic bonding. The obtained experimental data combined with the results of the DFT calculations reveal the effect of positional oscillations in the stability of consecutive chemical bonds{,} which has general character in chemistry." }Paola De Padova, Amanda Generosi, Barbara Paci, Carlo Ottaviani, Claudio Quaresima, Bruno Olivieri, Marek Kopciuszyński, Lucyna Żurawek, Ryszard Zdyb and Mariusz Krawiec.
New Findings on Multilayer Silicene on Si(111)√3×√3R30°–Ag Template.
Materials 12(14), July 2019.
Abstract We report new findings on multilayer silicene grown on Si(111)√3 × √3 R30°–Ag template, after the recent first compelling experimental evidence of its synthesis. Low-energy electron diffraction, reflection high-energy electron diffraction, and energy-dispersive grazing incidence X-ray diffraction measurements were performed to show up the fingerprints of √3 × √3 multilayer silicene. Angle-resolved photoemission spectroscopy displayed new features in the second surface Brillouin zone, attributed to the multilayer silicene on Si(111)√3 × √3 R30°–Ag. Band-structure dispersion theoretical calculations performed on a model of three honeycomb stacked layers, silicene grown on Si(111)√3 × √3 R30°-Ag surface confirm the experimental results. URL, DOI BibTeX@article{ma12142258, author = "De Padova, Paola and Generosi, Amanda and Paci, Barbara and Ottaviani, Carlo and Quaresima, Claudio and Olivieri, Bruno and Kopciuszyński, Marek and Żurawek, Lucyna and Zdyb, Ryszard and Krawiec, Mariusz", title = "New Findings on Multilayer Silicene on Si(111)√3×√3R30°–Ag Template", journal = "Materials", volume = 12, year = 2019, month = "Jul", number = 14, article-number = 2258, url = "https://www.mdpi.com/1996-1944/12/14/2258", pubmedid = 31337057, issn = "1996-1944", abstract = "We report new findings on multilayer silicene grown on Si(111)√3 × √3 R30°–Ag template, after the recent first compelling experimental evidence of its synthesis. Low-energy electron diffraction, reflection high-energy electron diffraction, and energy-dispersive grazing incidence X-ray diffraction measurements were performed to show up the fingerprints of √3 × √3 multilayer silicene. Angle-resolved photoemission spectroscopy displayed new features in the second surface Brillouin zone, attributed to the multilayer silicene on Si(111)√3 × √3 R30°–Ag. Band-structure dispersion theoretical calculations performed on a model of three honeycomb stacked layers, silicene grown on Si(111)√3 × √3 R30°-Ag surface confirm the experimental results.", doi = "10.3390/ma12142258" }Agnieszka Stȩpniak-Dybala and Mariusz Krawiec.
Formation of Silicene on Ultrathin Pb(111) Films.
The Journal of Physical Chemistry C 123:17019, June 2019.
Abstract The great success of graphene has spurred huge interest in two-dimensional honeycomb lattices of post-carbon group-14 atoms, namely, Xenes. However, the synthesis of Xenes on supporting substrates remains a big challenge due to the problem of Xene–substrate interaction. Recently, Pb(111) layers have been proposed as potential supports for silicene, the silicon follower of graphene. Using scanning tunneling microscopy and spectroscopy supported by ab initio density functional theory calculations, we reveal the epitaxial growth of silicene nanosheets on ultrathin Pb(111) films. Direct deposition of silicon on the Pb substrate results in two different discrete Si phases: √3 × √3 covered and 1 × 1 uncovered silicene structures. Scanning tunneling microscopy and spectroscopy measurements clearly display an atomically resolved low-buckled silicene honeycomb lattice in the uncovered phase. The covered phase represents the case of the Si(111)√3 × √3–Pb reconstruction on the thinnest Si substrate in the form of a single silicene layer. URL, DOI BibTeX@article{doi:10.1021/acs.jpcc.9b04343, author = "Stȩpniak-Dybala, Agnieszka and Krawiec, Mariusz", title = "Formation of Silicene on Ultrathin Pb(111) Films", journal = "The Journal of Physical Chemistry C", volume = 123, pages = 17019, year = 2019, month = "Jun", doi = "10.1021/acs.jpcc.9b04343", url = "https://doi.org/10.1021/acs.jpcc.9b04343", eprint = "https://doi.org/10.1021/acs.jpcc.9b04343", abstract = "The great success of graphene has spurred huge interest in two-dimensional honeycomb lattices of post-carbon group-14 atoms, namely, Xenes. However, the synthesis of Xenes on supporting substrates remains a big challenge due to the problem of Xene–substrate interaction. Recently, Pb(111) layers have been proposed as potential supports for silicene, the silicon follower of graphene. Using scanning tunneling microscopy and spectroscopy supported by ab initio density functional theory calculations, we reveal the epitaxial growth of silicene nanosheets on ultrathin Pb(111) films. Direct deposition of silicon on the Pb substrate results in two different discrete Si phases: √3 × √3 covered and 1 × 1 uncovered silicene structures. Scanning tunneling microscopy and spectroscopy measurements clearly display an atomically resolved low-buckled silicene honeycomb lattice in the uncovered phase. The covered phase represents the case of the Si(111)√3 × √3–Pb reconstruction on the thinnest Si substrate in the form of a single silicene layer." }M Hermanowicz, W Koczorowski, M Bazarnik, M Kopciuszyński, R Zdyb, A Materna, A Hruban, R Czajka and M W Radny.
Stable bismuth sub-monolayer termination of Bi2Se3.
Applied Surface Science 476:701, May 2019.
Abstract Surface electronic properties of Bi2Se3 and Bi2Te3 topological insulators are known to evolve with varying surface termination. In this work, the (111) surface of Bi2Se3 has been studied with a comprehensive combination of experimental and computational (density functional theory) methods. It has been demonstrated that with proper preparation conditions the system can be forced into a new stable surface termination – a sub-monolayer of bismuth acquired through selective Se desorption – which has not been explored yet. URL, DOI BibTeX@article{HERMANOWICZ2019701, abstract = "Surface electronic properties of Bi2Se3 and Bi2Te3 topological insulators are known to evolve with varying surface termination. In this work, the (111) surface of Bi2Se3 has been studied with a comprehensive combination of experimental and computational (density functional theory) methods. It has been demonstrated that with proper preparation conditions the system can be forced into a new stable surface termination -- a sub-monolayer of bismuth acquired through selective Se desorption -- which has not been explored yet.", author = "M. Hermanowicz and W. Koczorowski and M. Bazarnik and M. Kopciuszy{\'n}ski and R. Zdyb and A. Materna and A. Hruban and R. Czajka and M.W. Radny", doi = "10.1016/j.apsusc.2019.01.011", issn = "0169-4332", journal = "Applied Surface Science", keywords = "Bismuth selenide, Surface electronic structure, Surface termination, Topological insulator", month = "May", pages = 701, title = "Stable bismuth sub-monolayer termination of Bi2Se3", url = "http://www.sciencedirect.com/science/article/pii/S0169433219300170", volume = 476, year = 2019 }Marcin Kurzyna and Tomasz Kwapiński.
Electronic properties of atomic ribbons with spin-orbit couplings on different substrates.
Journal of Applied Physics 125:144301, April 2019.
Abstract Atomic ribbons and monoatomic chains on different substrates are proposed as spin-dependent electrical conductors with asymmetrical local density of states (DOS) and ferromagnetic occupancies along the chains. The tight-binding Hamiltonian and Green’s function techniques were used to analyze the electrical properties of both normal and topological systems with spin-orbit scattering. To make the system more realistic, electron leakage from atomic chains to various types of substrates is considered. We have shown that delocalized electrons in the substrate and spin-orbit interactions are responsible for asymmetry in the local DOS. The structure of DOS for spin-orbit nontopological chains is spin-dependent at both chain edges; however, in the middle of the chain, only paramagnetic solutions are observed. Additionally, we have found different periods of the local DOS oscillations along the chain in the presence of spin-flip and spin-orbit couplings. For topological chains, the edge nontrivial states split in the presence of spin-orbit scattering and spin-dependent Friedel oscillations appear along the whole topological chain. We have also found out-of-phase Friedel oscillations between neighboring chains along the atomic ribbon. URL, DOI BibTeX@article{doi:10.1063/1.5080651, author = "Kurzyna,Marcin and Kwapiński,Tomasz", title = "Electronic properties of atomic ribbons with spin-orbit couplings on different substrates", journal = "Journal of Applied Physics", volume = 125, pages = 144301, year = 2019, month = "Apr", doi = "10.1063/1.5080651", url = "https://doi.org/10.1063/1.5080651", eprint = "https://doi.org/10.1063/1.5080651", abstract = "Atomic ribbons and monoatomic chains on different substrates are proposed as spin-dependent electrical conductors with asymmetrical local density of states (DOS) and ferromagnetic occupancies along the chains. The tight-binding Hamiltonian and Green’s function techniques were used to analyze the electrical properties of both normal and topological systems with spin-orbit scattering. To make the system more realistic, electron leakage from atomic chains to various types of substrates is considered. We have shown that delocalized electrons in the substrate and spin-orbit interactions are responsible for asymmetry in the local DOS. The structure of DOS for spin-orbit nontopological chains is spin-dependent at both chain edges; however, in the middle of the chain, only paramagnetic solutions are observed. Additionally, we have found different periods of the local DOS oscillations along the chain in the presence of spin-flip and spin-orbit couplings. For topological chains, the edge nontrivial states split in the presence of spin-orbit scattering and spin-dependent Friedel oscillations appear along the whole topological chain. We have also found out-of-phase Friedel oscillations between neighboring chains along the atomic ribbon." }R Taranko, T Kwapiński and T Domański.
Transient dynamics of a quantum dot embedded between two superconducting leads and a metallic reservoir.
Phys. Rev. B 99:165419, April 2019.
Abstract We study time-dependent subgap properties of a quantum dot (QD) embedded between two superconductors and another metallic lead, solving the Heisenberg equations of motion by the Laplace transform technique subject to the initial conditions. Focusing on the response of the system induced by a sudden coupling of the QD to external reservoirs, we analyze the transient currents and their differential conductance. We also derive analytical expressions for measurable quantities and find that they oscillate in time with the frequency governed by the QD coupling to superconducting reservoirs. Such quantum oscillations are damped due to relaxation processes caused by the normal lead, whereas their period is controlled by the phase difference PHI between the order parameters of superconducting leads (except the case PHI=PI, when all observables evolve to their stationary values without any oscillations). We also explore time-dependent development of the subgap quasiparticles and find their signatures measurable in the differential conductance. We evaluate (numerically and analytically) three typical time scales, characterizing the initial and large-time stages of the transient dynamics which in the asymptotic limit (t->inf) drives these subgap quasiparticles to the true Andreev states. URL, DOI BibTeX@article{PhysRevB.99.165419, title = "Transient dynamics of a quantum dot embedded between two superconducting leads and a metallic reservoir", author = "Taranko, R. and Kwapiński, T. and Domański, T.", journal = "Phys. Rev. B", volume = 99, issue = 16, pages = 165419, numpages = 17, year = 2019, month = "Apr", publisher = "American Physical Society", doi = "10.1103/PhysRevB.99.165419", url = "https://link.aps.org/doi/10.1103/PhysRevB.99.165419", abstract = "We study time-dependent subgap properties of a quantum dot (QD) embedded between two superconductors and another metallic lead, solving the Heisenberg equations of motion by the Laplace transform technique subject to the initial conditions. Focusing on the response of the system induced by a sudden coupling of the QD to external reservoirs, we analyze the transient currents and their differential conductance. We also derive analytical expressions for measurable quantities and find that they oscillate in time with the frequency governed by the QD coupling to superconducting reservoirs. Such quantum oscillations are damped due to relaxation processes caused by the normal lead, whereas their period is controlled by the phase difference PHI between the order parameters of superconducting leads (except the case PHI=PI, when all observables evolve to their stationary values without any oscillations). We also explore time-dependent development of the subgap quasiparticles and find their signatures measurable in the differential conductance. We evaluate (numerically and analytically) three typical time scales, characterizing the initial and large-time stages of the transient dynamics which in the asymptotic limit (t->inf) drives these subgap quasiparticles to the true Andreev states." }Ryszard Zdyb and Ernst Bauer.
Quantum size effect in exchange asymmetry of ultrathin ferromagnetic films studied with Spin Polarized Low Energy Electron Microscopy.
Applied Surface Science 471:342, March 2019.
Abstract The magnetic properties of ultrathin ferromagnetic films are studied by means of Spin Polarized Low Energy Electron Microscopy. Measurements of the onset of ferromagnetic order, distribution and shape of magnetic domains, magnetization direction and their change are now well established standards for this technique. Here, the asymmetry parameter has been determined as a function of film coverage and energy of the incident electron beam. It reveals oscillatory behavior which is usually described as due to the quantum size effect (QSE). We explore the origin of the characteristic features observed in the asymmetry curves and distinguish between the QSE oscillations and other phenomena influencing the shape of the asymmetry curves. As an example we discuss the asymmetry of ultrathin iron films grown on the W(110) surface. URL, DOI BibTeX@article{ZDYB2019342, abstract = "The magnetic properties of ultrathin ferromagnetic films are studied by means of Spin Polarized Low Energy Electron Microscopy. Measurements of the onset of ferromagnetic order, distribution and shape of magnetic domains, magnetization direction and their change are now well established standards for this technique. Here, the asymmetry parameter has been determined as a function of film coverage and energy of the incident electron beam. It reveals oscillatory behavior which is usually described as due to the quantum size effect (QSE). We explore the origin of the characteristic features observed in the asymmetry curves and distinguish between the QSE oscillations and other phenomena influencing the shape of the asymmetry curves. As an example we discuss the asymmetry of ultrathin iron films grown on the W(110) surface.", author = "Ryszard Zdyb and Ernst Bauer", doi = "10.1016/j.apsusc.2018.11.215", issn = "0169-4332", journal = "Applied Surface Science", keywords = "Ultrathin ferromagnetic films, QSE, SPLEEM, Fe, W(110)", month = "March", pages = 342, title = "Quantum size effect in exchange asymmetry of ultrathin ferromagnetic films studied with Spin Polarized Low Energy Electron Microscopy", url = "http://www.sciencedirect.com/science/article/pii/S0169433218332902", volume = 471, year = 2019 }
2018
Z Korczak and T Kwapiński.
Thermal Annealing of Pb Films on Modified Silicon Surface: Electrical Conductance Measurement.
Acta Physica Polonica A 134(6):1211–1216, December 2018.
Abstract The electron transport properties of thin Pb films on Si(111)–(6x6)Au surface are studied experimentally using the four-point probe method and reflection high-energy electron diffraction system in UHV condition. We have measured the electrical conductance of the substrate with deposited at liquid nitrogen temperature Pb atoms during annealing and cooling down. We have found that the conductance increases during this process and from comparison of both heating and cooling curves the Pb recrystallization temperature was determined. Moreover, it was shown that 4 ML thick Pb film reveals temperature dependence of the conductance corresponding to the metallic bulk structure with the temperature coefficient of resistivity equal to 0.0036 1/K. To describe theoretically the conductance of thin Pb films the modified Trivedi-Ashcroft theory with temperature dependence of the roughness function was used in our calculations. URL, DOI BibTeX@article{Kor18, abstract = "The electron transport properties of thin Pb films on Si(111)--(6x6)Au surface are studied experimentally using the four-point probe method and reflection high-energy electron diffraction system in UHV condition. We have measured the electrical conductance of the substrate with deposited at liquid nitrogen temperature Pb atoms during annealing and cooling down. We have found that the conductance increases during this process and from comparison of both heating and cooling curves the Pb recrystallization temperature was determined. Moreover, it was shown that 4 ML thick Pb film reveals temperature dependence of the conductance corresponding to the metallic bulk structure with the temperature coefficient of resistivity equal to 0.0036 1/K. To describe theoretically the conductance of thin Pb films the modified Trivedi-Ashcroft theory with temperature dependence of the roughness function was used in our calculations.", author = "Z. Korczak and T. Kwapi{\'n}ski", doi = "10.12693/aphyspola.134.1211", issn = "0587-4246", journal = "Acta Physica Polonica A", month = "Dec", number = 6, pages = "1211--1216", publisher = "Institute of Physics, Polish Academy of Sciences", title = "Thermal Annealing of Pb Films on Modified Silicon Surface: Electrical Conductance Measurement", url = "http://dx.doi.org/10.12693/APhysPolA.134.1211", volume = 134, x-fetchedfrom = "DOI", year = 2018 }I Lutsyk, M Rogala, P Dabrowski, P Krukowski, P J Kowalczyk, A Busiakiewicz, D A Kowalczyk, E Lacinska, J Binder, N Olszowska, M Kopciuszynski, K Szalowski, M Gmitra, R Stepniewski, M Jalochowski, J J Kolodziej, A Wysmolek and Z Klusek.
Electronic structure of commensurate, nearly commensurate, and incommensurate phases of 1T-TaS2 by angle-resolved photoelectron spectroscopy, scanning tunneling spectroscopy, and density functional theory.
Phys. Rev. B 98:195425, November 2018.
Abstract The electronic structure of 1T−TaS2 showing a metal-insulator transition and a sequence of different charge density wave (CDW) transformations was discussed in the frame of variable temperature angle-resolved photoelectron spectroscopy (ARPES), scanning tunneling spectroscopy (STS), and density functional theory (DFT) calculations. For the commensurate charge density wave phase (CCDW) the Mott gap was estimated to be 0.4 eV and energy gaps Δ CCDW,1, ΔCCDW,2, ΔB3−HHB,ΔB4−B3 were observed. For the nearly commensurate charge density wave phase (NCCDW), the reminiscent of higher and lower Hubbard bands and a very pronounced electronic state associated with the parabolic band at the Γ point in the Brillouin zone were identified. The incommensurate charge density wave phase (ICCDW) showed a high value of local density of states at the Fermi level and a very pronounced edge of the metallic surface state located in the range of 0.15–0.20 eV above the Fermi level. The obtained STS and ARPES results were consistent with our theoretical calculations performed within DFT formalism including spin-orbit coupling. URL, DOI BibTeX@article{PhysRevB.98.195425, title = "Electronic structure of commensurate, nearly commensurate, and incommensurate phases of 1T-TaS2 by angle-resolved photoelectron spectroscopy, scanning tunneling spectroscopy, and density functional theory", author = "Lutsyk, I. and Rogala, M. and Dabrowski, P. and Krukowski, P. and Kowalczyk, P. J. and Busiakiewicz, A. and Kowalczyk, D. A. and Lacinska, E. and Binder, J. and Olszowska, N. and Kopciuszynski, M. and Szalowski, K. and Gmitra, M. and Stepniewski, R. and Jalochowski, M. and Kolodziej, J. J. and Wysmolek, A. and Klusek, Z.", journal = "Phys. Rev. B", volume = 98, issue = 19, pages = 195425, numpages = 14, year = 2018, month = "Nov", publisher = "American Physical Society", doi = "10.1103/PhysRevB.98.195425", url = "https://link.aps.org/doi/10.1103/PhysRevB.98.195425", abstract = "The electronic structure of 1T−TaS2 showing a metal-insulator transition and a sequence of different charge density wave (CDW) transformations was discussed in the frame of variable temperature angle-resolved photoelectron spectroscopy (ARPES), scanning tunneling spectroscopy (STS), and density functional theory (DFT) calculations. For the commensurate charge density wave phase (CCDW) the Mott gap was estimated to be 0.4 eV and energy gaps Δ CCDW,1, ΔCCDW,2, ΔB3−HHB,ΔB4−B3 were observed. For the nearly commensurate charge density wave phase (NCCDW), the reminiscent of higher and lower Hubbard bands and a very pronounced electronic state associated with the parabolic band at the Γ point in the Brillouin zone were identified. The incommensurate charge density wave phase (ICCDW) showed a high value of local density of states at the Fermi level and a very pronounced edge of the metallic surface state located in the range of 0.15–0.20 eV above the Fermi level. The obtained STS and ARPES results were consistent with our theoretical calculations performed within DFT formalism including spin-orbit coupling." }Klaudyna Krzyżewska, Tomasz Jaroch, Agnieszka Maranda-Niedbała, Damian Pociecha, Ewa Górecka, Ziauddin Ahmed, Chris Welch, Georg H Mehl, Adam Proń and Robert Nowakowski.
Supramolecular organization of liquid-crystal dimers – bis-cyanobiphenyl alkanes on HOPG by scanning tunneling microscopy.
Nanoscale 10:16201, August 2018.
Abstract 2D supramolecular organization of a series of six cyanobiphenyls bimesogens deposited on highly oriented pyrolytic graphite (HOPG) is studied by scanning tunneling microscopy (STM). The adsorbates are 1,ω-bis(4-cyanobiphenyl-4′-yl)alkanes (CBnCB) with different lengths of their flexible alkyl spacer (containing from 7 to 12 methylene groups). Microscopic investigations at the molecular resolution allow for detailed analysis of the effect of the alkyl spacer length on the type and the extent of the resulting 2D organization. It was demonstrated that bimesogens with shorter spacers (7 and 8 methylene units) organize in a similar manner characterized by the formation of two types of differently ordered monolayers: dense packed, wherein the molecules are oriented in one direction and ordered into parallel rows (layer structure), or less densely packed where they are organized into a chiral windmill-like structure. For derivatives with longer spacers (ranging from 9 to 12 methylene units) the additional effect of parity of carbon atoms in the spacer (even versus odd) is observed. In this range of the spacer lengths even membered bimesogens are also organized in a typical layer structure. However, odd-membered dimers exhibit a much more complex 2D supramolecular organization with a larger unit cell and a helical arrangement of the molecules. Careful comparison of this structure with the 3D structural data derived from the X-ray diffraction investigations of single crystals indicates that for these bimesogens a clear correlation exists between the observed complex 2D supramolecular organization in the monolayer and the organization in one of the crystallographic planes of the 3D nematic twist-bent phase. URL, DOI BibTeX@article{C8NR02069H, author = "Krzyżewska, Klaudyna and Jaroch, Tomasz and Maranda-Niedba{\l}a, Agnieszka and Pociecha, Damian and G{\'o}recka, Ewa and Ahmed, Ziauddin and Welch, Chris and Mehl, Georg H. and Pro{\'n}, Adam and Nowakowski, Robert", doi = "10.1039/C8NR02069H", journal = "Nanoscale", month = "Aug", pages = 16201, publisher = "The Royal Society of Chemistry", title = "Supramolecular organization of liquid-crystal dimers -- bis-cyanobiphenyl alkanes on HOPG by scanning tunneling microscopy", url = "http://dx.doi.org/10.1039/C8NR02069H", volume = 10, year = 2018, abstract = "2D supramolecular organization of a series of six cyanobiphenyls bimesogens deposited on highly oriented pyrolytic graphite (HOPG) is studied by scanning tunneling microscopy (STM). The adsorbates are 1,ω-bis(4-cyanobiphenyl-4′-yl)alkanes (CBnCB) with different lengths of their flexible alkyl spacer (containing from 7 to 12 methylene groups). Microscopic investigations at the molecular resolution allow for detailed analysis of the effect of the alkyl spacer length on the type and the extent of the resulting 2D organization. It was demonstrated that bimesogens with shorter spacers (7 and 8 methylene units) organize in a similar manner characterized by the formation of two types of differently ordered monolayers: dense packed, wherein the molecules are oriented in one direction and ordered into parallel rows (layer structure), or less densely packed where they are organized into a chiral windmill-like structure. For derivatives with longer spacers (ranging from 9 to 12 methylene units) the additional effect of parity of carbon atoms in the spacer (even versus odd) is observed. In this range of the spacer lengths even membered bimesogens are also organized in a typical layer structure. However, odd-membered dimers exhibit a much more complex 2D supramolecular organization with a larger unit cell and a helical arrangement of the molecules. Careful comparison of this structure with the 3D structural data derived from the X-ray diffraction investigations of single crystals indicates that for these bimesogens a clear correlation exists between the observed complex 2D supramolecular organization in the monolayer and the organization in one of the crystallographic planes of the 3D nematic twist-bent phase." }Mariusz Krawiec.
Functionalization of group-14 two-dimensional materials.
Journal of Physics: Condensed Matter 30:233003, May 2018.
Abstract The great success of graphene has boosted intensive search for other single-layer thick materials, mainly composed of group-14 atoms arranged in a honeycomb lattice. This new class of two-dimensional (2D) crystals, known as 2D-Xenes, has become an emerging field of intensive research due to their remarkable electronic properties and the promise for a future generation of nanoelectronics. In contrast to graphene, Xenes are not completely planar, and feature a low buckled geometry with two sublattices displaced vertically as a result of the interplay between sp2 and sp3 orbital hybridization. In spite of the buckling, the outstanding electronic properties of graphene governed by Dirac physics are preserved in Xenes too. The buckled structure also has several advantages over graphene. Together with the spin–orbit (SO) interaction it may lead to the emergence of various experimentally accessible topological phases, like the quantum spin Hall effect. This in turn would lead to designing and building new electronic and spintronic devices, like topological field effect transistors. In this regard an important issue concerns the electron energy gap, which for Xenes naturally exists owing to the buckling and SO interaction. The electronic properties, including the magnitude of the energy gap, can further be tuned and controlled by external means. Xenes can easily be functionalized by substrate, chemical adsorption, defects, charge doping, external electric field, periodic potential, in-plane uniaxial and biaxial stress, and out-of-plane long-range structural deformation, to name a few. This topical review explores structural, electronic and magnetic properties of Xenes and addresses the question of their functionalization in various ways, including external factors acting simultaneously. It also points to future directions to be explored in functionalization of Xenes. The results of experimental and theoretical studies obtained so far have many promising features making the 2D-Xene materials important players in the field of future nanoelectronics and spintronics. URL, DOI BibTeX@article{Krawiec_2018, author = "Krawiec, Mariusz", doi = "10.1088/1361-648x/aac149", journal = "Journal of Physics: Condensed Matter", month = "May", pages = 233003, title = "Functionalization of group-14 two-dimensional materials", url = "http://dx.doi.org/10.1088/1361-648X/aac149", volume = 30, year = 2018, abstract = "The great success of graphene has boosted intensive search for other single-layer thick materials, mainly composed of group-14 atoms arranged in a honeycomb lattice. This new class of two-dimensional (2D) crystals, known as 2D-Xenes, has become an emerging field of intensive research due to their remarkable electronic properties and the promise for a future generation of nanoelectronics. In contrast to graphene, Xenes are not completely planar, and feature a low buckled geometry with two sublattices displaced vertically as a result of the interplay between sp2 and sp3 orbital hybridization. In spite of the buckling, the outstanding electronic properties of graphene governed by Dirac physics are preserved in Xenes too. The buckled structure also has several advantages over graphene. Together with the spin–orbit (SO) interaction it may lead to the emergence of various experimentally accessible topological phases, like the quantum spin Hall effect. This in turn would lead to designing and building new electronic and spintronic devices, like topological field effect transistors. In this regard an important issue concerns the electron energy gap, which for Xenes naturally exists owing to the buckling and SO interaction. The electronic properties, including the magnitude of the energy gap, can further be tuned and controlled by external means. Xenes can easily be functionalized by substrate, chemical adsorption, defects, charge doping, external electric field, periodic potential, in-plane uniaxial and biaxial stress, and out-of-plane long-range structural deformation, to name a few. This topical review explores structural, electronic and magnetic properties of Xenes and addresses the question of their functionalization in various ways, including external factors acting simultaneously. It also points to future directions to be explored in functionalization of Xenes. The results of experimental and theoretical studies obtained so far have many promising features making the 2D-Xene materials important players in the field of future nanoelectronics and spintronics." }Marcin Kurzyna and Tomasz Kwapiński.
Non-local electron transport through normal and topological ladder-like atomic systems.
Journal of Applied Physics 123:194301, May 2018.
Abstract We propose a locally protected ladder-like atomic system (nanoconductor) on a substrate that is insensitive to external perturbations. The system corresponds to coupled atomic chains fabricated on different surfaces. Electron transport properties of such conductors are studied theoretically using the model tight-binding Su-Schriffer-Hegger (SSH) Hamiltonian and Green's function formalism. We have found that the conductance of the system is almost insensitive to single adatoms and oscillates as a function of the side chain length with very large periods. Non-local character of the electron transport was observed also for topological SSH chains where nontrivial end states survive in the presence of disturbances as well as for different substrates. We have found that the careful inspection of the density of states or charge waves can provide the information about the atom energy levels and hopping amplitudes. Moreover, the ladder-like geometry allows one to distinguish between normal and topological zero-energy states. It is important that topological chains do not reveal Friedel oscillations which are observed in non-topological chains. URL, DOI BibTeX@article{doi:10.1063/1.5028571, author = "Kurzyna, Marcin and Kwapi{\'n}ski, Tomasz", doi = "10.1063/1.5028571", eprint = "https://doi.org/10.1063/1.5028571", journal = "Journal of Applied Physics", month = "May", pages = 194301, title = "Non-local electron transport through normal and topological ladder-like atomic systems", url = "https://doi.org/10.1063/1.5028571", volume = 123, year = 2018, abstract = "We propose a locally protected ladder-like atomic system (nanoconductor) on a substrate that is insensitive to external perturbations. The system corresponds to coupled atomic chains fabricated on different surfaces. Electron transport properties of such conductors are studied theoretically using the model tight-binding Su-Schriffer-Hegger (SSH) Hamiltonian and Green's function formalism. We have found that the conductance of the system is almost insensitive to single adatoms and oscillates as a function of the side chain length with very large periods. Non-local character of the electron transport was observed also for topological SSH chains where nontrivial end states survive in the presence of disturbances as well as for different substrates. We have found that the careful inspection of the density of states or charge waves can provide the information about the atom energy levels and hopping amplitudes. Moreover, the ladder-like geometry allows one to distinguish between normal and topological zero-energy states. It is important that topological chains do not reveal Friedel oscillations which are observed in non-topological chains." }
2017
Pawel Dabrowski, Maciej Rogala, Iwona Pasternak, Jacek Baranowski, Wlodzimierz Strupinski, Marek Kopciuszynski, Ryszard Zdyb, Mieczyslaw Jalochowski, Iaroslav Lutsyk and Zbigniew Klusek.
The study of the interactions between graphene and Ge(001)/Si(001).
Nano Research 10:3648, November 2017.
Abstract The interaction between graphene and germanium surfaces was investigated using a combination of microscopic and macroscopic experimental techniques and complementary theoretical calculations. Density functional theory (DFT) calculations for different reconstructions of the Ge(001) surface showed that the interactions between graphene and the Ge(001) surface introduce additional peaks in the density of states, superimposed on the graphene valence and conduction energy bands. The growth of graphene induces nanofaceting of the Ge(001) surface, which exhibits well-organized hill and valley structures. The graphene regions covered by hills are of high quality and exhibit an almost linear dispersion relation, which indicates weak graphene–germanium interactions. On the other hand, the graphene component occupying valley regions is significantly perturbed by the interaction with germanium. It was also found that the stronger graphene–germanium interaction observed in the valley regions is connected with a lower local electrical conductivity. Annealing of graphene/Ge(001)/Si(001) was performed to obtain a more uniform surface. This process results in a surface characterized by negligible hill and valley structures; however, the graphene properties unexpectedly deteriorated with increasing uniformity of the Ge(001) surface. To sum up, it was shown that the mechanism responsible for the formation of local conductivity inhomogeneities in graphene covering the Ge(001) surface is related to the different strength of graphene–germanium interactions. The present results indicate that, in order to obtain high-quality graphene, the experimental efforts should focus on limiting the interactions between germanium and graphene, which can be achieved by adjusting the growth conditions. URL, DOI BibTeX@article{Dabrowski_2017, author = "Dabrowski, Pawel and Rogala, Maciej and Pasternak, Iwona and Baranowski, Jacek and Strupinski, Wlodzimierz and Kopciuszynski, Marek and Zdyb, Ryszard and Jalochowski, Mieczyslaw and Lutsyk, Iaroslav and Klusek, Zbigniew", doi = "10.1007/s12274-017-1575-6", journal = "Nano Research", pages = 3648, title = "The study of the interactions between graphene and Ge(001)/Si(001)", url = "http://dx.doi.org/10.1007/s12274-017-1575-6", volume = 10, month = "Nov", year = 2017, abstract = "The interaction between graphene and germanium surfaces was investigated using a combination of microscopic and macroscopic experimental techniques and complementary theoretical calculations. Density functional theory (DFT) calculations for different reconstructions of the Ge(001) surface showed that the interactions between graphene and the Ge(001) surface introduce additional peaks in the density of states, superimposed on the graphene valence and conduction energy bands. The growth of graphene induces nanofaceting of the Ge(001) surface, which exhibits well-organized hill and valley structures. The graphene regions covered by hills are of high quality and exhibit an almost linear dispersion relation, which indicates weak graphene–germanium interactions. On the other hand, the graphene component occupying valley regions is significantly perturbed by the interaction with germanium. It was also found that the stronger graphene–germanium interaction observed in the valley regions is connected with a lower local electrical conductivity. Annealing of graphene/Ge(001)/Si(001) was performed to obtain a more uniform surface. This process results in a surface characterized by negligible hill and valley structures; however, the graphene properties unexpectedly deteriorated with increasing uniformity of the Ge(001) surface. To sum up, it was shown that the mechanism responsible for the formation of local conductivity inhomogeneities in graphene covering the Ge(001) surface is related to the different strength of graphene–germanium interactions. The present results indicate that, in order to obtain high-quality graphene, the experimental efforts should focus on limiting the interactions between germanium and graphene, which can be achieved by adjusting the growth conditions." }Paola De Padova, Haifeng Feng, Jincheng Zhuang, Zhi Li, Amanda Generosi, Barbara Paci, Carlo Ottaviani, Claudio Quaresima, Bruno Olivieri and Mariusz Krawiec.
Synthesis of Multilayer Silicene on Si(111)3x3-Ag.
The Journal of Physical Chemistry C 121:27182, November 2017.
Abstract The compelling experimental evidence of multilayer silicene synthesis on one monolayer of silver deposited on a silicon substrate, Si(111)√3 × √3-Ag, used as a template is reported. Auger electron spectroscopy, low-energy electron diffraction, scanning tunneling microscopy/spectroscopy, in situ Raman spectroscopy, and energy-dispersive in-plane X-ray diffraction were applied to achieve the fingerprints of √3 × √3 multilayer silicene. Density functional theory calculations provided the structural models of single, bilayer, and three-layer silicene on the Si(111)√3 × √3-Ag surface. Single-layer silicene retains its free-standing form. The structural models, which are consistent with the experimental findings, feature atomic structure substantially different from that of Si(111). URL, DOI BibTeX@article{De_Padova_2017, author = "{De Padova}, Paola and Feng, Haifeng and Zhuang, Jincheng and Li, Zhi and Generosi, Amanda and Paci, Barbara and Ottaviani, Carlo and Quaresima, Claudio and Olivieri, Bruno and Krawiec, Mariusz", doi = "10.1021/acs.jpcc.7b09286", journal = "The Journal of Physical Chemistry C", pages = 27182, title = "Synthesis of Multilayer Silicene on Si(111)3x3-Ag", url = "http://dx.doi.org/10.1021/acs.jpcc.7b09286", volume = 121, month = "Nov", year = 2017, abstract = "The compelling experimental evidence of multilayer silicene synthesis on one monolayer of silver deposited on a silicon substrate, Si(111)√3 × √3-Ag, used as a template is reported. Auger electron spectroscopy, low-energy electron diffraction, scanning tunneling microscopy/spectroscopy, in situ Raman spectroscopy, and energy-dispersive in-plane X-ray diffraction were applied to achieve the fingerprints of √3 × √3 multilayer silicene. Density functional theory calculations provided the structural models of single, bilayer, and three-layer silicene on the Si(111)√3 × √3-Ag surface. Single-layer silicene retains its free-standing form. The structural models, which are consistent with the experimental findings, feature atomic structure substantially different from that of Si(111)." }R Zdyb and E Bauer.
Spin-dependent phase shift at ferromagnetic film interfaces from the reflectivity of slow electrons.
Physical Review B 96:205408, November 2017.
Abstract We report on spin-dependent phase shift of the electron wave reflected at the film/vacuum and film/substrate interfaces for electrons with energies above the vacuum level. The phase shift is determined within the Fabry-Pérot interferometer model of an absorbing medium, which takes into account the band structure of film and substrate. The results obtained for the model system Fe/W(110) indicate that the phase shift has nonzero values in the entire investigated energy range (up to 20 eV), including the energies of the allowed states in the substrate. This is in contrast to the available models which give zero phase shift for those energy ranges. It is also shown that the spin dependence is much stronger for the Fe/vacuum than for the Fe/W interface. URL, DOI BibTeX@article{Zdyb_2017, author = "Zdyb, R. and Bauer, E.", doi = "10.1103/physrevb.96.205408", pages = 205408, journal = "Physical Review B", publisher = "American Physical Society (APS)", title = "Spin-dependent phase shift at ferromagnetic film interfaces from the reflectivity of slow electrons", url = "http://dx.doi.org/10.1103/PhysRevB.96.205408", volume = 96, month = "Nov", year = 2017, abstract = "We report on spin-dependent phase shift of the electron wave reflected at the film/vacuum and film/substrate interfaces for electrons with energies above the vacuum level. The phase shift is determined within the Fabry-Pérot interferometer model of an absorbing medium, which takes into account the band structure of film and substrate. The results obtained for the model system Fe/W(110) indicate that the phase shift has nonzero values in the entire investigated energy range (up to 20 eV), including the energies of the allowed states in the substrate. This is in contrast to the available models which give zero phase shift for those energy ranges. It is also shown that the spin dependence is much stronger for the Fe/vacuum than for the Fe/W interface." }D Wrana, C Rodenbücher, M Krawiec, B R Jany, J Rysz, M Ermrich, K Szot and F Krok.
Tuning the surface structure and conductivity of niobium-doped rutile TiO2 single crystals via thermal reduction.
Physical Chemistry Chemical Physics 19:30339, September 2017.
Abstract We report on the systematic exploration of electronic and structural changes of Nb-doped rutile TiO2(110) single crystal surfaces due to the thermoreduction under ultra-high vacuum conditions (without sputtering), with comparison to undoped TiO2(110) crystals. It has been found that the surface of the doped sample undergoes a previously unknown transition during reduction above 850 °C, as provided by LEED, STM and LC-AFM. This transition involves a change from heterogeneous conductivity (due to the presence of conducting filaments) to homogeneous conductivity, connected with a new (4 × 2) reconstruction of rows parallel to the [001] direction. DFT calculations suggest substitution of Ti by Nb atoms in the first atomic layer. Due to the strong reducing conditions during annealing, oxygen is released from the crystal and Nb diffuses from the subsurface into the bulk, agglomerating however on the surface, as shown by SIMS depth profiling. We present that 0.5% Nb doping significantly influences the reduction process and in turn the structural properties of the surface by supporting the evolution of the new reconstruction. It is shown that the thermal treatment of TiO2:Nb under low oxygen partial pressure gives an opportunity to tune the electrical conductivity and work function of the surface. URL, DOI BibTeX@article{Wrana_2017, author = {Wrana, D. and Rodenb{\"u}cher, C. and Krawiec, M. and Jany, B. R. and Rysz, J. and Ermrich, M. and Szot, K. and Krok, F.}, doi = "10.1039/c7cp03136j", journal = "Physical Chemistry Chemical Physics", pages = 30339, publisher = "Royal Society of Chemistry (RSC)", title = "Tuning the surface structure and conductivity of niobium-doped rutile TiO2 single crystals via thermal reduction", url = "http://dx.doi.org/10.1039/C7CP03136J", volume = 19, month = "Sep", year = 2017, abstract = "We report on the systematic exploration of electronic and structural changes of Nb-doped rutile TiO2(110) single crystal surfaces due to the thermoreduction under ultra-high vacuum conditions (without sputtering), with comparison to undoped TiO2(110) crystals. It has been found that the surface of the doped sample undergoes a previously unknown transition during reduction above 850 °C, as provided by LEED, STM and LC-AFM. This transition involves a change from heterogeneous conductivity (due to the presence of conducting filaments) to homogeneous conductivity, connected with a new (4 × 2) reconstruction of rows parallel to the [001] direction. DFT calculations suggest substitution of Ti by Nb atoms in the first atomic layer. Due to the strong reducing conditions during annealing, oxygen is released from the crystal and Nb diffuses from the subsurface into the bulk, agglomerating however on the surface, as shown by SIMS depth profiling. We present that 0.5% Nb doping significantly influences the reduction process and in turn the structural properties of the surface by supporting the evolution of the new reconstruction. It is shown that the thermal treatment of TiO2:Nb under low oxygen partial pressure gives an opportunity to tune the electrical conductivity and work function of the surface." }Agnieszka Stępniak-Dybala and Mariusz Krawiec.
Structural model of silicene-like nanoribbons on a Pb-reconstructed Si(111) surface.
Beilstein Journal of Nanotechnology 8:1836, September 2017.
Abstract A structural model of the recently observed silicene-like nanoribbons on a Pb-induced √3 × √3 reconstructed Si(111) surface is proposed. The model, which is based on first principles density functional theory calculations, features a deformed honeycomb structure directly bonded to the Si(111) surface underneath. Pb atoms stabilize the nanoribbons, as they passivate the uncovered substrate, thus lower the surface energy, and suppress the nanoribbon–substrate interaction. The proposed structural model reproduces well all the experimental findings. URL, DOI BibTeX@article{St_pniak_Dybala_2017, author = "Stępniak-Dybala, Agnieszka and Krawiec, Mariusz", doi = "10.3762/bjnano.8.185", journal = "Beilstein Journal of Nanotechnology", pages = 1836, publisher = "Beilstein Institut", title = "Structural model of silicene-like nanoribbons on a Pb-reconstructed Si(111) surface", url = "http://dx.doi.org/10.3762/bjnano.8.185", volume = 8, month = "Sep", year = 2017, abstract = "A structural model of the recently observed silicene-like nanoribbons on a Pb-induced √3 × √3 reconstructed Si(111) surface is proposed. The model, which is based on first principles density functional theory calculations, features a deformed honeycomb structure directly bonded to the Si(111) surface underneath. Pb atoms stabilize the nanoribbons, as they passivate the uncovered substrate, thus lower the surface energy, and suppress the nanoribbon–substrate interaction. The proposed structural model reproduces well all the experimental findings." }Rafal Zuzak, Ruth Dorel, Mariusz Krawiec, Bartosz Such, Marek Kolmer, Marek Szymonski, Antonio M Echavarren and Szymon Godlewski.
Nonacene Generated by On-Surface Dehydrogenation.
ACS Nano 11:9321, August 2017.
Abstract The on-surface synthesis of nonacene has been accomplished by dehydrogenation of an air-stable partially saturated precursor, which could be aromatized by using a combined scanning tunneling and atomic force microscope as well as by on-surface annealing. This transformation allowed the in-detail analysis of the electronic properties of nonacene molecules physisorbed on Au(111) by scanning tunneling spectroscopy measurements. The spatial mapping of molecular orbitals was corroborated by density functional theory calculations. Furthermore, the thermally induced dehydrogenation uncovered the isomerization of intermediate dihydrononacene species, which allowed for their in-depth structural and electronic characterization. URL, DOI BibTeX@article{doi:10.1021/acsnano.7b04728, author = "Zuzak, Rafal and Dorel, Ruth and Krawiec, Mariusz and Such, Bartosz and Kolmer, Marek and Szymonski, Marek and Echavarren, Antonio M. and Godlewski, Szymon", doi = "10.1021/acsnano.7b04728", eprint = "https://doi.org/10.1021/acsnano.7b04728", journal = "ACS Nano", pages = 9321, title = "Nonacene Generated by On-Surface Dehydrogenation", url = "https://doi.org/10.1021/acsnano.7b04728", volume = 11, month = "Aug", year = 2017, abstract = "The on-surface synthesis of nonacene has been accomplished by dehydrogenation of an air-stable partially saturated precursor, which could be aromatized by using a combined scanning tunneling and atomic force microscope as well as by on-surface annealing. This transformation allowed the in-detail analysis of the electronic properties of nonacene molecules physisorbed on Au(111) by scanning tunneling spectroscopy measurements. The spatial mapping of molecular orbitals was corroborated by density functional theory calculations. Furthermore, the thermally induced dehydrogenation uncovered the isomerization of intermediate dihydrononacene species, which allowed for their in-depth structural and electronic characterization." }Agata Podsiadły-Paszkowska and Mariusz Krawiec.
Rehybridization-induced charge density oscillations in the long-range corrugated silicene.
Physical Chemistry Chemical Physics 19:14269, May 2017.
Abstract Freestanding silicene is a one-atom-thick two-dimensional material composed of Si atoms arranged in a honeycomb lattice that is related to graphene. Its low-buckled atomic structure facilitates the functionalization of silicene. We report on an alternative method of functionalization which utilizes one-dimensional long-range periodic structural deformation of silicene, and leads to rehybridization-induced sublattice-polarized charge density oscillations. The charge density modulation follows the structural deformation of silicene, and features opposite phases in different sublattices. The modulated atomic structure leads to anisotropy of electron group velocity and to opening of a band gap that grows and oscillates with increasing corrugation. We show that rippled silicene can be considered as a combination of a silicene nanoribbon and a part of a silicon nanotube. The existence of the charge density oscillation phase is a consequence of the layer corrugation and the tendency of silicon toward sp3 bonding. One-dimensional structural modulation appears to be a powerful method of silicene functionalization, and the predicted phase is expected to be realized in other two-dimensional materials, which prefer sp3 bonding. URL, DOI BibTeX@article{Podsiad_y_Paszkowska_2017, author = "Podsiad{\l}y-Paszkowska, Agata and Krawiec, Mariusz", doi = "10.1039/c7cp02352a", journal = "Physical Chemistry Chemical Physics", pages = 14269, publisher = "Royal Society of Chemistry (RSC)", title = "Rehybridization-induced charge density oscillations in the long-range corrugated silicene", url = "http://dx.doi.org/10.1039/C7CP02352A", volume = 19, month = "May", year = 2017, abstract = "Freestanding silicene is a one-atom-thick two-dimensional material composed of Si atoms arranged in a honeycomb lattice that is related to graphene. Its low-buckled atomic structure facilitates the functionalization of silicene. We report on an alternative method of functionalization which utilizes one-dimensional long-range periodic structural deformation of silicene{,} and leads to rehybridization-induced sublattice-polarized charge density oscillations. The charge density modulation follows the structural deformation of silicene{,} and features opposite phases in different sublattices. The modulated atomic structure leads to anisotropy of electron group velocity and to opening of a band gap that grows and oscillates with increasing corrugation. We show that rippled silicene can be considered as a combination of a silicene nanoribbon and a part of a silicon nanotube. The existence of the charge density oscillation phase is a consequence of the layer corrugation and the tendency of silicon toward sp3 bonding. One-dimensional structural modulation appears to be a powerful method of silicene functionalization{,} and the predicted phase is expected to be realized in other two-dimensional materials{,} which prefer sp3 bonding." }Marek Kopciuszyński, Mariusz Krawiec, Ryszard Zdyb and Mieczysław Jałochowski.
Purely one-dimensional bands with a giant spin-orbit splitting: Pb nanoribbons on Si (553) surface.
Scientific Reports 7:46215, April 2017.
Abstract We report on a giant Rashba type splitting of metallic bands observed in one-dimensional structures prepared on a vicinal silicon substrate. A single layer of Pb on Si(553) orders this vicinal surface making perfectly regular distribution of monatomic steps. Although there is only one layer of Pb, the system reveals very strong metallic and purely one-dimensional character, which manifests itself in multiple surface state bands crossing the Fermi level in the direction parallel to the step edges and a small band gap in the perpendicular direction. As shown by spin-polarized photoemission and density functional theory calculations these surface state bands are spin-polarized and completely decoupled from the rest of the system. The experimentally observed spin splitting of 0.6 eV at room temperature is the largest found to now in the silicon-based metallic nanostructures, which makes the considered system a promising candidate for application in spintronic devices. URL, DOI BibTeX@article{kopciuszynski2017purely, author = "Kopciuszy{\'n}ski, Marek and Krawiec, Mariusz and Zdyb, Ryszard and Ja{\l}ochowski, Mieczys{\l}aw", journal = "Scientific Reports", url = "https://www.nature.com/articles/srep46215", doi = "10.1038/srep46215", pages = 46215, publisher = "Nature Publishing Group", title = "Purely one-dimensional bands with a giant spin-orbit splitting: Pb nanoribbons on Si (553) surface", volume = 7, month = "Apr", year = 2017, abstract = "We report on a giant Rashba type splitting of metallic bands observed in one-dimensional structures prepared on a vicinal silicon substrate. A single layer of Pb on Si(553) orders this vicinal surface making perfectly regular distribution of monatomic steps. Although there is only one layer of Pb, the system reveals very strong metallic and purely one-dimensional character, which manifests itself in multiple surface state bands crossing the Fermi level in the direction parallel to the step edges and a small band gap in the perpendicular direction. As shown by spin-polarized photoemission and density functional theory calculations these surface state bands are spin-polarized and completely decoupled from the rest of the system. The experimentally observed spin splitting of 0.6 eV at room temperature is the largest found to now in the silicon-based metallic nanostructures, which makes the considered system a promising candidate for application in spintronic devices." }M Kopciuszyński, A Mandziak, M Dachniewicz and R Zdyb.
Regular distribution of(3x3)Bi-reconstructed stripes on Si(553) surface.
Thin Solid Films 631:80, March 2017.
Abstract The crystallographic and electronic structures of (r3xr3) Bi-induced reconstructions of Si(553) surface are investigated with reflection high energy electron diffraction (RHEED), scanning tunneling microscopy and angle resolved photoelectron spectroscopy. The α(r3xr3) and β(r3xr3) superstructures have been obtained at 1/3 and 1 monolayer of Bi, respectively. RHEED experiments indicate that is formed on wide (111) terraces separated by (331) facets while the phase stabilizes regular distribution of steps over entire Si(553) surface. In the latter case the double atomic height steps separate Bi-reconstructed (111) terraces of about 3 nm in width. Only one (r3xr3) orientation of reconstruction is formed as a consequence of broken three-fold symmetry. The electronic structures of both Bi-induced superstructures are similar to the corresponding ones obtained for a flat Si(111) surface. URL, DOI BibTeX@article{Kopciuszy_ski_2017, author = "Kopciuszy{\'n}ski, M. and Mandziak, A. and Dachniewicz, M. and Zdyb, R.", doi = "10.1016/j.tsf.2017.03.052", journal = "Thin Solid Films", pages = 80, title = "Regular distribution of(3x3)Bi-reconstructed stripes on Si(553) surface", url = "http://dx.doi.org/10.1016/j.tsf.2017.03.052", volume = 631, month = "Mar", year = 2017, abstract = "The crystallographic and electronic structures of (r3xr3) Bi-induced reconstructions of Si(553) surface are investigated with reflection high energy electron diffraction (RHEED), scanning tunneling microscopy and angle resolved photoelectron spectroscopy. The α(r3xr3) and β(r3xr3) superstructures have been obtained at 1/3 and 1 monolayer of Bi, respectively. RHEED experiments indicate that is formed on wide (111) terraces separated by (331) facets while the phase stabilizes regular distribution of steps over entire Si(553) surface. In the latter case the double atomic height steps separate Bi-reconstructed (111) terraces of about 3 nm in width. Only one (r3xr3) orientation of reconstruction is formed as a consequence of broken three-fold symmetry. The electronic structures of both Bi-induced superstructures are similar to the corresponding ones obtained for a flat Si(111) surface." }Tomasz Kwapiński.
DOS cones along atomic chains.
Journal of Physics: Condensed Matter 29:095304, January 2017.
Abstract The electron transport properties of a linear atomic chain are studied theoretically within the tight-binding Hamiltonian and the Green\rqs function method. Variations of the local density of states (DOS) along the chain are investigated. They are crucial in scanning tunnelling experiments and give important insight into the electron transport mechanism and charge distribution inside chains. It is found that depending on the chain parity the local DOS at the Fermi level can form cone-like structures (DOS cones) along the chain. The general condition for the local DOS oscillations is obtained and the linear behaviour of the local density function is confirmed analytically. DOS cones are characterized by a linear decay towards the chain which is in contrast to the propagation properties of charge density waves, end states and Friedel oscillations in one-dimensional systems. We find that DOS cones can appear due to non-resonant electron transport, the spin–orbit scattering or for chains fabricated on a substrate with localized electrons. It is also shown that for imperfect chains (e.g. with a reduced coupling strength between two neighboring sites) a diamond-like structure of the local DOS along the chain appears. URL, DOI BibTeX@article{0953-8984-29-9-095304, abstract = "The electron transport properties of a linear atomic chain are studied theoretically within the tight-binding Hamiltonian and the Green{\rq}s function method. Variations of the local density of states (DOS) along the chain are investigated. They are crucial in scanning tunnelling experiments and give important insight into the electron transport mechanism and charge distribution inside chains. It is found that depending on the chain parity the local DOS at the Fermi level can form cone-like structures (DOS cones) along the chain. The general condition for the local DOS oscillations is obtained and the linear behaviour of the local density function is confirmed analytically. DOS cones are characterized by a linear decay towards the chain which is in contrast to the propagation properties of charge density waves, end states and Friedel oscillations in one-dimensional systems. We find that DOS cones can appear due to non-resonant electron transport, the spin--orbit scattering or for chains fabricated on a substrate with localized electrons. It is also shown that for imperfect chains (e.g. with a reduced coupling strength between two neighboring sites) a diamond-like structure of the local DOS along the chain appears.", author = "Kwapi{\'n}ski, Tomasz", journal = "Journal of Physics: Condensed Matter", pages = 095304, title = "DOS cones along atomic chains", url = "http://stacks.iop.org/0953-8984/29/i=9/a=095304", doi = "10.1088/1361-648X/aa5540", volume = 29, month = "Jan", year = 2017 }Agata Podsiadły-Paszkowska and Mariusz Krawiec.
Tuning the Electronic Structure of Hydrogen-Decorated Silicene.
Condensed Matter 2:1, December 2016.
Abstract The effects of strain, charge doping, and external electric field on the electronic structure of a free-standing silicene layer decorated by hydrogen atoms are studied by first-principles density functional theory. Various phases, including insulating, metallic, spin-polarized, and half-metallic have been found, depending on these external factors. The most efficient way of switching the system between these phases is charge doping. The character of the energy gap of the H/silicene system can also be modified, and for charged or for strained systems, the originally indirect gap can be tuned to become direct. The obtained results are very promising in view of the silicene functionalization and potential applications of silicene in the fields of spintronics and optoelectronics. URL, DOI BibTeX@article{Podsiad_y_Paszkowska_2016, author = "Podsiad{\l}y-Paszkowska, Agata and Krawiec, Mariusz", doi = "10.3390/condmat2010001", journal = "Condensed Matter", pages = 1, title = "Tuning the Electronic Structure of Hydrogen-Decorated Silicene", url = "http://dx.doi.org/10.3390/condmat2010001", volume = 2, month = "Dec", year = 2016, abstract = "The effects of strain, charge doping, and external electric field on the electronic structure of a free-standing silicene layer decorated by hydrogen atoms are studied by first-principles density functional theory. Various phases, including insulating, metallic, spin-polarized, and half-metallic have been found, depending on these external factors. The most efficient way of switching the system between these phases is charge doping. The character of the energy gap of the H/silicene system can also be modified, and for charged or for strained systems, the originally indirect gap can be tuned to become direct. The obtained results are very promising in view of the silicene functionalization and potential applications of silicene in the fields of spintronics and optoelectronics." }
2016
Mirosław Stróżak, Marek Kopciuszyński, Agnieszka Stępniak-Dybala, Mariusz Krawiec and Mieczysław Jałochowski.
Early Stage of Sb Ultra-Thin Film Growth: Crystal Structure and Electron Band Structure.
Condensed Matter 1:11, December 2016.
Abstract The evolution of the electron band structure upon the reduction of Sb film on a Si(111)-(6 × 6)Au substrate, relevant to topological insulator properties, is experimentally systematically investigated by the reflection high-energy electron diffraction (RHEED), in situ surface electron transport and angular resolved photoemission spectroscopy methods. The experiments reveal that a bilayer (BL) of Sb is crystalline but the subsequent three BLs on top of it form amorphous layers. The five-BL-thick film transforms back to the crystalline form. The bilayer as well as 1.2- and 3.8-BL-thick films show the electron band structure with a relatively large energy gap at the Γ point of the Brillouin zone. The theoretically predicted band structure is observed at 4.8 BL coverage. URL, DOI BibTeX@article{Str_ak_2016, author = "Stróżak, Miros{\l}aw and Kopciuszy{\'n}ski, Marek and Stępniak-Dybala, Agnieszka and Krawiec, Mariusz and Ja{\l}ochowski, Mieczys{\l}aw", doi = "10.3390/condmat1010011", journal = "Condensed Matter", pages = 11, title = "Early Stage of Sb Ultra-Thin Film Growth: Crystal Structure and Electron Band Structure", url = "http://dx.doi.org/10.3390/condmat1010011", volume = 1, year = 2016, abstract = "The evolution of the electron band structure upon the reduction of Sb film on a Si(111)-(6 × 6)Au substrate, relevant to topological insulator properties, is experimentally systematically investigated by the reflection high-energy electron diffraction (RHEED), in situ surface electron transport and angular resolved photoemission spectroscopy methods. The experiments reveal that a bilayer (BL) of Sb is crystalline but the subsequent three BLs on top of it form amorphous layers. The five-BL-thick film transforms back to the crystalline form. The bilayer as well as 1.2- and 3.8-BL-thick films show the electron band structure with a relatively large energy gap at the Γ point of the Brillouin zone. The theoretically predicted band structure is observed at 4.8 BL coverage.", month = "Dec" }Agnieszka Stępniak-Dybala, Mieczysław Jałochowski and Mariusz Krawiec.
Silicene Nanoribbons on Pb-Reconstructed Si(111) Surface.
Condensed Matter 1:8, December 2016.
Abstract We report on the initial stage of growing of silicon nanostructures on Pb-induced √3×√3 and √3×√7 reconstructed Si(111) surfaces. The deposition of 0.75 monolayer of Si at a temperature of around 200 K results in Si nanoribbons a few-nanometers in length running in three equivalent high symmetry directions of Si(111) surface, as revealed by low temperature scanning tunneling microscopy measurements. The nanoribbons are predominantly 1.6 nm wide and show local √3×√3 reconstruction. These findings are interpreted within the framework of silicene nanoribbons grown on a bare Si(111) surface. URL, DOI BibTeX@article{St_pniak_Dybala_2016, author = "Stępniak-Dybala, Agnieszka and Ja{\l}ochowski, Mieczys{\l}aw and Krawiec, Mariusz", doi = "10.3390/condmat1010008", journal = "Condensed Matter", pages = 8, title = "Silicene Nanoribbons on Pb-Reconstructed Si(111) Surface", url = "http://dx.doi.org/10.3390/condmat1010008", volume = 1, year = 2016, abstract = "We report on the initial stage of growing of silicon nanostructures on Pb-induced √3×√3 and √3×√7 reconstructed Si(111) surfaces. The deposition of 0.75 monolayer of Si at a temperature of around 200 K results in Si nanoribbons a few-nanometers in length running in three equivalent high symmetry directions of Si(111) surface, as revealed by low temperature scanning tunneling microscopy measurements. The nanoribbons are predominantly 1.6 nm wide and show local √3×√3 reconstruction. These findings are interpreted within the framework of silicene nanoribbons grown on a bare Si(111) surface.", month = "Dec" }M Jałochowski, K Palotás and M Krawiec.
Spilling of electronic states in Pb quantum wells.
Phys. Rev. B 93:035437, November 2016.
Abstract Energy-dependent apparent step heights of two-dimensional ultrathin Pb islands grown on the Si(111)6x6−Au surface have been investigated by a combination of scanning tunneling microscopy, first-principles density-functional theory, and the particle-in-a-box model calculations. The apparent step height shows the thickness- and energy-dependent oscillatory behaviors, which are directly related to the spilling of electron states into the vacuum exhibiting a quantum size effect. This has been unambiguously proven by extensive first-principles scanning tunneling microscopy and spectroscopy simulations. An electronic contribution to the apparent step height is directly determined. At certain energies it reaches values as high as a half of the atomic contribution. The applicability of the particle-in-a-box model to the spilling of electron states is also discussed. URL, DOI BibTeX@article{PhysRevB.93.035437, author = "Ja{\l}ochowski, M. and Palot{\'a}s, K. and Krawiec, M.", doi = "10.1103/PhysRevB.93.035437", journal = "Phys. Rev. B", pages = 035437, title = "Spilling of electronic states in Pb quantum wells", url = "https://link.aps.org/doi/10.1103/PhysRevB.93.035437", volume = 93, year = 2016, abstract = "Energy-dependent apparent step heights of two-dimensional ultrathin Pb islands grown on the Si(111)6x6−Au surface have been investigated by a combination of scanning tunneling microscopy, first-principles density-functional theory, and the particle-in-a-box model calculations. The apparent step height shows the thickness- and energy-dependent oscillatory behaviors, which are directly related to the spilling of electron states into the vacuum exhibiting a quantum size effect. This has been unambiguously proven by extensive first-principles scanning tunneling microscopy and spectroscopy simulations. An electronic contribution to the apparent step height is directly determined. At certain energies it reaches values as high as a half of the atomic contribution. The applicability of the particle-in-a-box model to the spilling of electron states is also discussed.", month = "Nov" }M Kopciuszyński, R Zdyb, P Nita, M Dachniewicz and P Dyniec.
Quasi one-dimensional lead ribbons on the Si(110) surface.
Applied Surface Science 373:8, June 2016.
Abstract The crystallographic structure of quasi one-dimensional lead ribbons prepared on Si(110) surface is investigated with reflection high energy electron diffraction and scanning tunneling microscopy. Deposition of 2.6 monolayers of lead with subsequent annealing at 260 C results in the formation of anisotropic metallic structures ordered over macroscopic area. The lead ribbons grow along [-110] which is a unique direction for this surface and form a single domain system contrary to pristine Si(110)-(16×2) or (7×2)-Pb reconstructions that extend along equivalent <112> directions. Diffraction and STM experiments reveal the 16.3 A periodicity along the [001] direction and multilevel structure of the ribbons. URL, DOI BibTeX@article{Kopciuszy_ski_2016, author = "Kopciuszy{\'n}ski, M. and Zdyb, R. and Nita, P. and Dachniewicz, M. and Dyniec, P.", doi = "10.1016/j.apsusc.2015.11.147", journal = "Applied Surface Science", pages = 8, title = "Quasi one-dimensional lead ribbons on the Si(110) surface", url = "http://dx.doi.org/10.1016/j.apsusc.2015.11.147", volume = 373, year = 2016, abstract = "The crystallographic structure of quasi one-dimensional lead ribbons prepared on Si(110) surface is investigated with reflection high energy electron diffraction and scanning tunneling microscopy. Deposition of 2.6 monolayers of lead with subsequent annealing at 260 C results in the formation of anisotropic metallic structures ordered over macroscopic area. The lead ribbons grow along [-110] which is a unique direction for this surface and form a single domain system contrary to pristine Si(110)-(16×2) or (7×2)-Pb reconstructions that extend along equivalent <112> directions. Diffraction and STM experiments reveal the 16.3 A periodicity along the [001] direction and multilevel structure of the ribbons.", month = "Jun" }M Krawiec, M Kopciuszyński and R Zdyb.
Different spin textures in one-dimensional electronic bands on Si(553)-Au surface.
Applied Surface Science 373:26, June 2016.
Abstract A doublet of one-dimensional metallic bands on Au-stabilized Si(5 5 3) surface features different splitting due to the spin–orbit interaction. Density functional theory calculations reveal the origin of unequal magnitude of the splitting. Furthermore, different orientations of spin polarizations, almost perpendicular to each other, in both spin–orbit split bands are discovered. These observations are consistent with the Rashba effect and induced electric field in the system with out-of-plane and in-plane components. The results of calculations are confirmed by spin- and angle-resolved photoelectron spectroscopy measurements. The Si(5 5 3)-Au surface appears as a unique 1D Rashba system. URL, DOI BibTeX@article{Krawiec_2016, author = "Krawiec, M. and Kopciuszy{\'n}ski, M. and Zdyb, R.", doi = "10.1016/j.apsusc.2015.09.219", journal = "Applied Surface Science", pages = 26, title = "Different spin textures in one-dimensional electronic bands on Si(553)-Au surface", url = "http://dx.doi.org/10.1016/j.apsusc.2015.09.219", volume = 373, year = 2016, abstract = "A doublet of one-dimensional metallic bands on Au-stabilized Si(5 5 3) surface features different splitting due to the spin–orbit interaction. Density functional theory calculations reveal the origin of unequal magnitude of the splitting. Furthermore, different orientations of spin polarizations, almost perpendicular to each other, in both spin–orbit split bands are discovered. These observations are consistent with the Rashba effect and induced electric field in the system with out-of-plane and in-plane components. The results of calculations are confirmed by spin- and angle-resolved photoelectron spectroscopy measurements. The Si(5 5 3)-Au surface appears as a unique 1D Rashba system.", month = "Jun" }A Podsiadły-Paszkowska and M Krawiec.
Spin-polarized gapped Dirac spectrum of unsupported silicene.
Applied Surface Science 373:45, June 2016.
Abstract We study effects of the spin–orbit interaction and the atomic reconstruction of silicene on its electronic spectrum. As an example we consider unsupported silicene pulled off from Pb(111) substrate. Using first principles density functional theory we show that the inversion symmetry broken arrangement of atoms and the spin–orbit interaction generate a spin-polarized electronic spectrum with an energy gap in the Dirac cone. These findings are particularly interesting in view of the quantum anomalous and quantum valley Hall effects and should be observable in weakly interacting silicene-substrate systems. URL, DOI BibTeX@article{Podsiad_y_Paszkowska_2016_2, author = "Podsiad{\l}y-Paszkowska, A. and Krawiec, M.", doi = "10.1016/j.apsusc.2015.12.025", journal = "Applied Surface Science", pages = 45, title = "Spin-polarized gapped Dirac spectrum of unsupported silicene", url = "http://dx.doi.org/10.1016/j.apsusc.2015.12.025", volume = 373, year = 2016, abstract = "We study effects of the spin–orbit interaction and the atomic reconstruction of silicene on its electronic spectrum. As an example we consider unsupported silicene pulled off from Pb(111) substrate. Using first principles density functional theory we show that the inversion symmetry broken arrangement of atoms and the spin–orbit interaction generate a spin-polarized electronic spectrum with an energy gap in the Dirac cone. These findings are particularly interesting in view of the quantum anomalous and quantum valley Hall effects and should be observable in weakly interacting silicene-substrate systems.", month = "Jun" }R Zdyb and M Kopciuszyński.
Thickness-dependent spin-resolved photoemission from ultrathin Ag films on Si(111).
Applied Surface Science 373:73, June 2016.
Abstract Electronic structure of ultrathin Ag films on Si(111) is investigated with spin- and angle-resolved photoemission spectroscopy using unpolarized light. Photoelectrons leaving d states of Ag reveal spin polarization with the polarization vector parallel to the sample surface. The effect is observed for the Ag films which have bulk-like crystallographic structure with coverages down to 1 monolayer, for Ag wetting layer on Si(111)-(7 × 7) and Si(111)-√3×√3Ag surface. It is found that the polarization magnitude increases with Ag thickness. The observed changes have been attributed to the changes in the Ag film morphology. URL, DOI BibTeX@article{Zdyb_2016, author = "Zdyb, R. and Kopciuszy{\'n}ski, M.", doi = "10.1016/j.apsusc.2015.12.188", journal = "Applied Surface Science", pages = 73, title = "Thickness-dependent spin-resolved photoemission from ultrathin Ag films on Si(111)", url = "http://dx.doi.org/10.1016/j.apsusc.2015.12.188", volume = 373, year = 2016, abstract = "Electronic structure of ultrathin Ag films on Si(111) is investigated with spin- and angle-resolved photoemission spectroscopy using unpolarized light. Photoelectrons leaving d states of Ag reveal spin polarization with the polarization vector parallel to the sample surface. The effect is observed for the Ag films which have bulk-like crystallographic structure with coverages down to 1 monolayer, for Ag wetting layer on Si(111)-(7 × 7) and Si(111)-√3×√3Ag surface. It is found that the polarization magnitude increases with Ag thickness. The observed changes have been attributed to the changes in the Ag film morphology.", month = "Jun" }Agata Podsiadły-Paszkowska and Mariusz Krawiec.
Electrical and mechanical controlling of the kinetic and magnetic properties of hydrogen atoms on free-standing silicene.
Journal of Physics: Condensed Matter 28:284004, May 2016.
Abstract Effects of strain, charge doping and external electric field on kinetic and magnetic properties of hydrogen atoms on a free-standing silicene layer are investigated by first-principles density functional theory. It was found that the charge doping and strain are the most effective ways of changing the hydrogen-silicene binding energy, but they can only raise its value. The perpendicular external electric field can also lower it albeit in a narrower range. The strain has also the strongest impact on diffusion processes, and the diffusion barrier can be modified up to 50% of its unstrained value. The adsorption of hydrogen atoms results in a locally antiferromagnetic ground state with the effective exchange constant of approximately 1 eV. The system can easily be driven into a nonmagnetic phase by the charge doping and strain. The obtained results are very promising in view of the silicene functionalization and potential applications of silicene in fields of modern nanoelectronics and spintronics. URL, DOI BibTeX@article{Podsiad_y_Paszkowska_2016, author = "Podsiad{\l}y-Paszkowska, Agata and Krawiec, Mariusz", doi = "10.1088/0953-8984/28/28/284004", journal = "Journal of Physics: Condensed Matter", pages = 284004, title = "Electrical and mechanical controlling of the kinetic and magnetic properties of hydrogen atoms on free-standing silicene", url = "http://dx.doi.org/10.1088/0953-8984/28/28/284004", volume = 28, year = 2016, abstract = "Effects of strain, charge doping and external electric field on kinetic and magnetic properties of hydrogen atoms on a free-standing silicene layer are investigated by first-principles density functional theory. It was found that the charge doping and strain are the most effective ways of changing the hydrogen-silicene binding energy, but they can only raise its value. The perpendicular external electric field can also lower it albeit in a narrower range. The strain has also the strongest impact on diffusion processes, and the diffusion barrier can be modified up to 50% of its unstrained value. The adsorption of hydrogen atoms results in a locally antiferromagnetic ground state with the effective exchange constant of approximately 1 eV. The system can easily be driven into a nonmagnetic phase by the charge doping and strain. The obtained results are very promising in view of the silicene functionalization and potential applications of silicene in fields of modern nanoelectronics and spintronics.", month = "May" }M Jałochowski, T Kwapiński, P Łukasik, P Nita and M Kopciuszyński.
Correlation between morphology, electron band structure, and resistivity of Pb atomic chains on the Si(553)-Au surface.
Journal of Physics: Condensed Matter 28:284003, May 2016.
Abstract Structural and electron transport properties of multiple Pb atomic chains fabricated on the Si(5 5 3)-Au surface are investigated using scanning tunneling spectroscopy, reflection high electron energy diffraction, angular resolved photoemission electron spectroscopy and in situ electrical resistance. The study shows that Pb atomic chains growth modulates the electron band structure of pristine Si(5 5 3)-Au surface and hence changes its sheet resistivity. Strong correlation between chains morphology, electron band structure and electron transport properties is found. To explain experimental findings a theoretical tight-binding model of multiple atomic chains interacting on effective substrate is proposed. URL, DOI BibTeX@article{Ja_ochowski_2016, author = "Ja{\l}ochowski, M and Kwapi{\'n}ski, T and {\L}ukasik, P and Nita, P and Kopciuszy{\'n}ski, M", doi = "10.1088/0953-8984/28/28/284003", journal = "Journal of Physics: Condensed Matter", pages = 284003, title = "Correlation between morphology, electron band structure, and resistivity of Pb atomic chains on the Si(553)-Au surface", url = "http://dx.doi.org/10.1088/0953-8984/28/28/284003", volume = 28, year = 2016, abstract = "Structural and electron transport properties of multiple Pb atomic chains fabricated on the Si(5 5 3)-Au surface are investigated using scanning tunneling spectroscopy, reflection high electron energy diffraction, angular resolved photoemission electron spectroscopy and in situ electrical resistance. The study shows that Pb atomic chains growth modulates the electron band structure of pristine Si(5 5 3)-Au surface and hence changes its sheet resistivity. Strong correlation between chains morphology, electron band structure and electron transport properties is found. To explain experimental findings a theoretical tight-binding model of multiple atomic chains interacting on effective substrate is proposed.", month = "May" }M Jałochowski, R Zdyb and M C Tringides.
Correlations between In Situ Conductivity and Uniform-Height Epitaxial Morphology in Pb/Si(111)-7x7.
Phys. Rev. Lett. 116:086101, May 2016.
Abstract The growth of Pb on Si(111)−(7×7) at temperatures from 72 to 201 K has been investigated using in situ electrical resistivity measurements and scanning tunneling microscopy. For temperatures T>140 K the specific resistivity ρ(θ)versus coverage θ shows an unusual “hump,” instead of the expected monotonic decrease with θ. This novel result correlates well with the formation of uniform height eight-layer Pb islands and the superdiffusive motion of the wetting layer, despite the low temperatures. A model of the film resistivity as two resistors in series, the amorphous wetting layer and the crystalline islands, explains quantitatively the resi URL, DOI BibTeX@article{PhysRevLett.116.086101, author = "Ja{\l}ochowski, M. and Zdyb, R. and Tringides, M. C.", doi = "10.1103/PhysRevLett.116.086101", journal = "Phys. Rev. Lett.", pages = 086101, title = "Correlations between In Situ Conductivity and Uniform-Height Epitaxial Morphology in Pb/Si(111)-7x7", url = "https://link.aps.org/doi/10.1103/PhysRevLett.116.086101", volume = 116, year = 2016, abstract = "The growth of Pb on Si(111)−(7×7) at temperatures from 72 to 201 K has been investigated using in situ electrical resistivity measurements and scanning tunneling microscopy. For temperatures T>140 K the specific resistivity ρ(θ)versus coverage θ shows an unusual “hump,” instead of the expected monotonic decrease with θ. This novel result correlates well with the formation of uniform height eight-layer Pb islands and the superdiffusive motion of the wetting layer, despite the low temperatures. A model of the film resistivity as two resistors in series, the amorphous wetting layer and the crystalline islands, explains quantitatively the resi", month = "May" }
2015
Agata Podsiadły-Paszkowska and Mariusz Krawiec.
Dirac fermions in silicene on Pb(111) surface.
Physical Chemistry Chemical Physics 17(3):2246, December 2015.
Abstract First-principles density functional theory calculations of silicene deposited on a Pb(111) surface are reported. Several possible silicene superstructures, exhibiting different scanning tunnelling microscopy topography images have been found. All the structures feature low binding energy and very small charge transfer, thus interact weakly with the substrate. As a result linear band dispersion around the K points of the Brillouin zone survives and the bands have mainly 3p character of silicene with very little contribution of the 6p states of Pb. The present study suggests that lead can be the best candidate to host silicene among other metal substrates. URL, DOI BibTeX@article{Podsiad_y_Paszkowska_2015, author = "Podsiad{\l}y-Paszkowska, Agata and Krawiec, Mariusz", doi = "10.1039/c4cp05104a", journal = "Physical Chemistry Chemical Physics", number = 3, pages = 2246, publisher = "Royal Society of Chemistry (RSC)", title = "Dirac fermions in silicene on Pb(111) surface", url = "http://dx.doi.org/10.1039/C4CP05104A", volume = 17, year = 2015, month = "Dec", abstract = "First-principles density functional theory calculations of silicene deposited on a Pb(111) surface are reported. Several possible silicene superstructures, exhibiting different scanning tunnelling microscopy topography images have been found. All the structures feature low binding energy and very small charge transfer, thus interact weakly with the substrate. As a result linear band dispersion around the K points of the Brillouin zone survives and the bands have mainly 3p character of silicene with very little contribution of the 6p states of Pb. The present study suggests that lead can be the best candidate to host silicene among other metal substrates." }A Podsiadły-Paszkowska and M Krawiec.
Silicene on metallic quantum wells: An efficient way of tuning silicene-substrate interaction.
Phys. Rev. B 92:165411, October 2015.
Abstract We propose a powerful method for controlling interaction between silicene and a substrate utilizing quantum size effect, which allows growing silicene with tailored electronic properties. As an example we consider silicene on ultrathin Pb(111) layers and demonstrate how the properties of silicene, including the binding energy and the Dirac bands, can easily be tuned by quantum well states of the substrate. We also discover a novel mechanism of protecting the Dirac electrons from the influence of the substrate. This is associated with a special arrangement of a part of the Si atoms in silicene. These findings emphasize the essential role of interfacial coupling and open new routes to create silicenelike two-dimensional structures with controlled electronic properties. URL, DOI BibTeX@article{PhysRevB.92.165411, author = "Podsiad{\l}y-Paszkowska, A. and Krawiec, M.", doi = "10.1103/PhysRevB.92.165411", journal = "Phys. Rev. B", pages = 165411, title = "Silicene on metallic quantum wells: An efficient way of tuning silicene-substrate interaction", url = "https://link.aps.org/doi/10.1103/PhysRevB.92.165411", volume = 92, year = 2015, month = "Oct", abstract = "We propose a powerful method for controlling interaction between silicene and a substrate utilizing quantum size effect, which allows growing silicene with tailored electronic properties. As an example we consider silicene on ultrathin Pb(111) layers and demonstrate how the properties of silicene, including the binding energy and the Dirac bands, can easily be tuned by quantum well states of the substrate. We also discover a novel mechanism of protecting the Dirac electrons from the influence of the substrate. This is associated with a special arrangement of a part of the Si atoms in silicene. These findings emphasize the essential role of interfacial coupling and open new routes to create silicenelike two-dimensional structures with controlled electronic properties." }M Kopciuszyński, P Dyniec, R Zdyb and M Jałochowski.
Regular step distribution of the bare Si(553) surface.
Phys. Rev. B 91:235420, June 2015.
Abstract Vicinal Si(111) surfaces are known to undergo faceting when the temperature is lowered below the (1x1) to (7x7) phase transition temperature. Depending on the cutoff angle value and direction with respect to the crystallographic axis, various facets, together with low Miller index terraces, are formed. Here, we report the formation of regularly distributed steps over macroscopic sample regions of the bare Si(553) surface. The surface morphology is studied with scanning tunneling microscopy and reflection high energy electron diffraction techniques. The (111) terraces of 2.88 nm in width, which are separated by double atomic height steps, reveal an unusual reconstruction. However, the electronic structure determined with angle resolved photoemission spectroscopy shows bands very similar to those observed for the Si(111)-(7x7) surface. URL, DOI BibTeX@article{PhysRevB.91.235420, author = "{Kopciuszyński}, M. and Dyniec, P. and Zdyb, R. and Ja{\l}ochowski, M.", doi = "10.1103/PhysRevB.91.235420", journal = "Phys. Rev. B", pages = 235420, title = "Regular step distribution of the bare Si(553) surface", url = "https://link.aps.org/doi/10.1103/PhysRevB.91.235420", volume = 91, year = 2015, month = "Jun", abstract = "Vicinal Si(111) surfaces are known to undergo faceting when the temperature is lowered below the (1x1) to (7x7) phase transition temperature. Depending on the cutoff angle value and direction with respect to the crystallographic axis, various facets, together with low Miller index terraces, are formed. Here, we report the formation of regularly distributed steps over macroscopic sample regions of the bare Si(553) surface. The surface morphology is studied with scanning tunneling microscopy and reflection high energy electron diffraction techniques. The (111) terraces of 2.88 nm in width, which are separated by double atomic height steps, reveal an unusual reconstruction. However, the electronic structure determined with angle resolved photoemission spectroscopy shows bands very similar to those observed for the Si(111)-(7x7) surface." }P Dabrowski, M Rogala, I Wlasny, Z Klusek, M Kopciuszynski, M Jalochowski, W Strupinski and J M Baranowski.
Nitrogen doped epitaxial graphene on 4H-SiC(0001) – Experimental and theoretical study.
Carbon 94:214, June 2015.
Abstract The experimental and theoretical investigations of morphological and electronic properties of nitrogen-doped epitaxial graphene grown by chemical vapor deposition on 4H-SiC(0001) are discussed. It is shown that presence of nitrogen significantly affects the graphene growth process and leads to an increase in the concentration of defects (in the form of holes). Macro- and nanoscale investigations confirm the formation of pyridinic-N, pyrrolic-N and graphitic-N configurations within graphene layers. The relative concentrations of these configurations change as a function of global nitrogen concentration. Additionally, it is reported that the incorporated nitrogen results in inhomogeneous doping and a few nanometers wide spatial modification of the local density of states. Finally, the SiC substrate is also modified during the nitrogen doping process. To quantify the impact of the substrate modification on electronic structure of graphene the non-intercalated and hydrogen-intercalated doped graphene layers are compared. The presented complementary study sheds light on properties of N-doped graphene and its dependence on nitrogen concentration. URL, DOI BibTeX@article{Dabrowski_2015, author = "Dabrowski, P. and Rogala, M. and Wlasny, I. and Klusek, Z. and Kopciuszynski, M. and Jalochowski, M. and Strupinski, W. and Baranowski, J.M.", doi = "10.1016/j.carbon.2015.06.073", journal = "Carbon", pages = 214, title = "Nitrogen doped epitaxial graphene on 4H-SiC(0001) -- Experimental and theoretical study", url = "http://dx.doi.org/10.1016/j.carbon.2015.06.073", volume = 94, year = 2015, month = "Jun", abstract = "The experimental and theoretical investigations of morphological and electronic properties of nitrogen-doped epitaxial graphene grown by chemical vapor deposition on 4H-SiC(0001) are discussed. It is shown that presence of nitrogen significantly affects the graphene growth process and leads to an increase in the concentration of defects (in the form of holes). Macro- and nanoscale investigations confirm the formation of pyridinic-N, pyrrolic-N and graphitic-N configurations within graphene layers. The relative concentrations of these configurations change as a function of global nitrogen concentration. Additionally, it is reported that the incorporated nitrogen results in inhomogeneous doping and a few nanometers wide spatial modification of the local density of states. Finally, the SiC substrate is also modified during the nitrogen doping process. To quantify the impact of the substrate modification on electronic structure of graphene the non-intercalated and hydrogen-intercalated doped graphene layers are compared. The presented complementary study sheds light on properties of N-doped graphene and its dependence on nitrogen concentration." }Tomasz Kwapiński and Ryszard Taranko.
Mono-parametric charge pumping through a quantum dot coupled with energy-gapped leads.
88:140, June 2015.
Abstract We present a proposal for a single-parametric electron pump composed of a quantum dot between two unbiased leads with energy-gapped electron density of states (DOS). The model tight-binding Hamiltonian and the evolution operator technique are used in the calculations. The quantum dot is driven by the external harmonic field which leads to the pumping current flowing from the left or right electrode depending on the system parameters. We show that the net pumping current appears in the system if (i) there are at least two sideband states: one of them lying below and the second lying above the Fermi energy; (ii) the left and right lead DOS in the vicinity of these sideband states are different. Moreover, the energy-gapped structure of DOS is visible on the average quantum dot charge and the pumped current curves as well as on the transconductance characteristics. Thus mono-parametric pumping provides useful information about the system parameters, in particular about the lead DOS structure. URL, DOI BibTeX@article{Kwapi_ski_2015, author = "Kwapi{\'n}ski, Tomasz and Taranko, Ryszard", doi = "10.1140/epjb/e2015-60098-1", publisher = "Springer Nature", title = "Mono-parametric charge pumping through a quantum dot coupled with energy-gapped leads", url = "http://dx.doi.org/10.1140/epjb/e2015-60098-1", volume = 88, pages = 140, year = 2015, month = "Jun", abstract = "We present a proposal for a single-parametric electron pump composed of a quantum dot between two unbiased leads with energy-gapped electron density of states (DOS). The model tight-binding Hamiltonian and the evolution operator technique are used in the calculations. The quantum dot is driven by the external harmonic field which leads to the pumping current flowing from the left or right electrode depending on the system parameters. We show that the net pumping current appears in the system if (i) there are at least two sideband states: one of them lying below and the second lying above the Fermi energy; (ii) the left and right lead DOS in the vicinity of these sideband states are different. Moreover, the energy-gapped structure of DOS is visible on the average quantum dot charge and the pumped current curves as well as on the transconductance characteristics. Thus mono-parametric pumping provides useful information about the system parameters, in particular about the lead DOS structure." }M Kopciuszyński, P Dyniec, M Krawiec, M Jałochowski and R Zdyb.
Quantum size effect in ultrathin Au films on the Si(111) surface.
Applied Surface Science 331:512, March 2015.
Abstract The crystallographic and electronic structures of gold ultrathin layers grown on the Si(111)–(6x6)Au surface are investigated with the reflection high energy electron diffraction, scanning tunnelling microscopy, angle-resolved photoemission spectroscopy and density functional theory techniques. It is found that the Au layers consist of crystallites with the (111) and (110) orientations in respect to the Si substrate. Both types of crystallites contribute quantum size effect bands to the electronic structure of the film. It is observed in photoemission experiments as two sets of quantum states with significantly different dispersions. Almost linear bands are associated with the (111) crystallites while the parabolic-shaped ones belong to the (110)-oriented crystallites. The electronic structure is reproduced well by the first principle calculations. URL, DOI BibTeX@article{Kopciuszy_ski_2015, author = "Kopciuszy{\'n}ski, M. and Dyniec, P. and Krawiec, M. and Ja{\l}ochowski, M. and Zdyb, R.", doi = "10.1016/j.apsusc.2015.01.089", journal = "Applied Surface Science", pages = 512, title = "Quantum size effect in ultrathin Au films on the Si(111) surface", url = "http://dx.doi.org/10.1016/j.apsusc.2015.01.089", volume = 331, year = 2015, month = "Mar", abstract = "The crystallographic and electronic structures of gold ultrathin layers grown on the Si(111)–(6x6)Au surface are investigated with the reflection high energy electron diffraction, scanning tunnelling microscopy, angle-resolved photoemission spectroscopy and density functional theory techniques. It is found that the Au layers consist of crystallites with the (111) and (110) orientations in respect to the Si substrate. Both types of crystallites contribute quantum size effect bands to the electronic structure of the film. It is observed in photoemission experiments as two sets of quantum states with significantly different dispersions. Almost linear bands are associated with the (111) crystallites while the parabolic-shaped ones belong to the (110)-oriented crystallites. The electronic structure is reproduced well by the first principle calculations." }R Taranko and T Kwapiński.
Charge and current beats in T-shaped qubit–detector systems.
Physica E: Low-dimensional Systems and Nanostructures 70:217, March 2015.
Abstract The time evolution of a charge qubit coupled electrostatically with different detectors in the forms of single, double and triple quantum dot linear systems in the T-shaped configuration between two reservoirs is theoretically considered. The correspondence between the qubit quantum dot oscillations and the detector current is studied for different values of the inter-dot tunneling amplitudes and the qubit–detector interaction strength. We have found that even for a qubit coupled with a single QD detector, the coherent beat patterns appear in the oscillations of the qubit charge. This effect is more evident for a qubit coupled with double or triple-QD detectors. The beats can be also observed in both the detector current and the detector quantum dot occupations. Moreover, in the presence of beats the qubit oscillations hold longer in time in comparison with the beats-free systems with monotonously decaying oscillations. The dependence of the qubit dynamics on different initial occupations of the detector sites (memory effect) is also analyzed. URL, DOI BibTeX@article{Taranko_2015, author = "Taranko, R. and Kwapi{\'n}ski, T.", doi = "10.1016/j.physe.2015.03.013", journal = "Physica E: Low-dimensional Systems and Nanostructures", pages = 217, title = "Charge and current beats in T-shaped qubit--detector systems", url = "http://dx.doi.org/10.1016/j.physe.2015.03.013", volume = 70, year = 2015, month = "Mar", abstract = "The time evolution of a charge qubit coupled electrostatically with different detectors in the forms of single, double and triple quantum dot linear systems in the T-shaped configuration between two reservoirs is theoretically considered. The correspondence between the qubit quantum dot oscillations and the detector current is studied for different values of the inter-dot tunneling amplitudes and the qubit–detector interaction strength. We have found that even for a qubit coupled with a single QD detector, the coherent beat patterns appear in the oscillations of the qubit charge. This effect is more evident for a qubit coupled with double or triple-QD detectors. The beats can be also observed in both the detector current and the detector quantum dot occupations. Moreover, in the presence of beats the qubit oscillations hold longer in time in comparison with the beats-free systems with monotonously decaying oscillations. The dependence of the qubit dynamics on different initial occupations of the detector sites (memory effect) is also analyzed." }Mariusz Krawiec.
Undercover diffusion of atoms: Pb on Si(5 5 3)-Au surface covered by graphene.
Journal of Physics: Condensed Matter 27:125003, February 2015.
Abstract The diffusion of Pb atoms under a graphene layer deposited on a Si(553)-Au surface is studied by the first-principles density functional theory. The presence of graphene locks the moving Pb atoms inside tube-like closed objects, formed by grooves near steps of the Si(553)-Au surface and limited from the top by the graphene layer. As a result, the diffusion processes are well-separated from the environment. The methods of experimental verification of the undercover diffusion are also proposed. URL, DOI BibTeX@article{Krawiec_2015, author = "Krawiec, Mariusz", doi = "10.1088/0953-8984/27/12/125003", journal = "Journal of Physics: Condensed Matter", pages = 125003, title = "Undercover diffusion of atoms: Pb on Si(5 5 3)-Au surface covered by graphene", url = "http://dx.doi.org/10.1088/0953-8984/27/12/125003", volume = 27, year = 2015, month = "Feb", abstract = "The diffusion of Pb atoms under a graphene layer deposited on a Si(553)-Au surface is studied by the first-principles density functional theory. The presence of graphene locks the moving Pb atoms inside tube-like closed objects, formed by grooves near steps of the Si(553)-Au surface and limited from the top by the graphene layer. As a result, the diffusion processes are well-separated from the environment. The methods of experimental verification of the undercover diffusion are also proposed." }
2014
Jakub Ossowski, Jakub Rysz, Mariusz Krawiec, Dawid Maciazek, Zbigniew Postawa, Andreas Terfort and Piotr Cyganik.
Oscillations in the Stability of Consecutive Chemical Bonds Revealed by Ion-Induced Desorption.
Angewandte Chemie International Edition 54:1336, December 2014.
Abstract While it is a common concept in chemistry that strengthening of one bond results in weakening of the adjacent ones, no results have been published on if and how this effect protrudes further into the molecular backbone. By binding molecules to a surface in the form of a self‐assembled monolayer, the strength of a primary bond can be selectively altered. Herein, we report that by using secondary‐ion mass spectrometry, we are able to detect for the first time positional oscillations in the stability of consecutive bonds along the adsorbed molecule, with the amplitudes diminishing with increasing distance from the molecule–metal interface. To explain these observations, we have performed molecular dynamics simulations and DFT calculations. These show that the oscillation effects in chemical‐bond stability have a very general nature and break the translational symmetry in molecules. URL, DOI BibTeX@article{Ossowski_2014, author = "Ossowski, Jakub and Rysz, Jakub and Krawiec, Mariusz and Maciazek, Dawid and Postawa, Zbigniew and Terfort, Andreas and Cyganik, Piotr", doi = "10.1002/anie.201406053", journal = "Angewandte Chemie International Edition", pages = 1336, title = "Oscillations in the Stability of Consecutive Chemical Bonds Revealed by Ion-Induced Desorption", url = "http://dx.doi.org/10.1002/anie.201406053", volume = 54, year = 2014, abstract = "While it is a common concept in chemistry that strengthening of one bond results in weakening of the adjacent ones, no results have been published on if and how this effect protrudes further into the molecular backbone. By binding molecules to a surface in the form of a self‐assembled monolayer, the strength of a primary bond can be selectively altered. Herein, we report that by using secondary‐ion mass spectrometry, we are able to detect for the first time positional oscillations in the stability of consecutive bonds along the adsorbed molecule, with the amplitudes diminishing with increasing distance from the molecule–metal interface. To explain these observations, we have performed molecular dynamics simulations and DFT calculations. These show that the oscillation effects in chemical‐bond stability have a very general nature and break the translational symmetry in molecules.", month = "Dec" }M Kopciuszyński, R Zdyb and M Jałochowski.
Influence of Si(111) surface superstructure on quantum size effect in Au films.
Applied Surface Science 304:40, June 2014.
Abstract The influence of Si/Au interface on the appearance of the quantum size effect (QSE) in ultrathin Au films on Si(1 1 1) surface is investigated. Angle-resolved photoemission measurements indicate QSE states in Au layers grown on the Si(111) surface with the (7x7), (6x6)Au and (r3xr3)Ag reconstructions and show no QSE for the (r3xr3)Pb reconstruction. Reflection high energyelectron diffraction patterns indicate that the existence of the QSE states depends on the Au film morphology. URL, DOI BibTeX@article{Kopciuszy_ski_2014_2, author = "Kopciuszy{\'n}ski, M. and Zdyb, R. and Ja{\l}ochowski, M.", doi = "10.1016/j.apsusc.2013.11.025", issn = "0169-4332", journal = "Applied Surface Science", pages = 40, publisher = "Elsevier BV", title = "Influence of Si(111) surface superstructure on quantum size effect in Au films", url = "http://dx.doi.org/10.1016/j.apsusc.2013.11.025", volume = 304, x-fetchedfrom = "DOI", year = 2014, abstract = "The influence of Si/Au interface on the appearance of the quantum size effect (QSE) in ultrathin Au films on Si(1 1 1) surface is investigated. Angle-resolved photoemission measurements indicate QSE states in Au layers grown on the Si(111) surface with the (7x7), (6x6)Au and (r3xr3)Ag reconstructions and show no QSE for the (r3xr3)Pb reconstruction. Reflection high energyelectron diffraction patterns indicate that the existence of the QSE states depends on the Au film morphology.", month = "Jun" }M Kopciuszyński, P Łukasik, R Zdyb and M Jałochowski.
Ordering of the Si(553) surface with Pb atoms.
Applied Surface Science 305:139, June 2014.
Abstract The crystallographic structure and morphology of the Si(5 5 3) surface covered with Pb atoms are investigated with the reflection high energy electron diffraction (RHEED) technique. A regular distribution of steps over a macroscopic sample area is obtained after the adsorption of more than 1.3 monolayers Pb and subsequent annealing. The details of preparation of the ordered surface together with a diffraction model explaining the observed RHEED patterns are presented. The applied model predicts main diffraction features observed with RHEED and confirms the structural order of the surface. URL, DOI BibTeX@article{Kopciuszy_ski_2014, author = "Kopciuszy{\'n}ski, M. and {\L}ukasik, P. and Zdyb, R. and Ja{\l}ochowski, M.", doi = "10.1016/j.apsusc.2014.03.009", issn = "0169-4332", journal = "Applied Surface Science", pages = 139, publisher = "Elsevier BV", title = "Ordering of the Si(553) surface with Pb atoms", url = "http://dx.doi.org/10.1016/j.apsusc.2014.03.009", volume = 305, year = 2014, month = "Jun", abstract = "The crystallographic structure and morphology of the Si(5 5 3) surface covered with Pb atoms are investigated with the reflection high energy electron diffraction (RHEED) technique. A regular distribution of steps over a macroscopic sample area is obtained after the adsorption of more than 1.3 monolayers Pb and subsequent annealing. The details of preparation of the ordered surface together with a diffraction model explaining the observed RHEED patterns are presented. The applied model predicts main diffraction features observed with RHEED and confirms the structural order of the surface." }J M Urban, P Dąbrowski, J Binder, M Kopciuszyński, A Wysmołek, Z Klusek, M Jałochowski, W Strupiński and J M Baranowski.
Nitrogen doping of chemical vapor deposition grown graphene on 4H-SiC (0001).
Journal of Applied Physics 115:233504, June 2014.
Abstract We present optical, electrical, and structural properties of nitrogen-doped graphene grown on the Si face of 4H-SiC (0001) by chemical vapor deposition method using propane as the carbon precursor and N2 as the nitrogen source. The incorporation of nitrogen in the carbon lattice was confirmed by X-ray photoelectron spectroscopy. Angle-resolved photoemission spectroscopy shows carrier behavior characteristic for massless Dirac fermions and confirms the presence of a graphene monolayer in the investigated nitrogen-doped samples. The structural and electronic properties of the material were investigated by Raman spectroscopy. A systematical analysis of the graphene Raman spectra, including D, G, and 2D bands, was performed. In the case of nitrogen-doped samples, an electron concentration on the order of 5–10x10^12 cm^−2 was estimated based upon Raman and Hall effect measurements and no clear dependence of the carrier concentration on nitrogen concentration used during growth was observed. This high electron concentration can be interpreted as both due to the presence of nitrogen in graphitic-like positions of the graphene lattice as well as to the interaction with the substrate. A greater intensity of the Raman D band and increased inhomogeneity, as well as decreased electron mobility, observed for nitrogen-doped samples, indicate the formation of defects and a modification of the growth process induced by nitrogen doping. URL, DOI BibTeX@article{Urban_2014, author = "Urban, J. M. and Dąbrowski, P. and Binder, J. and Kopciuszy{\'n}ski, M. and Wysmo{\l}ek, A. and Klusek, Z. and Ja{\l}ochowski, M. and Strupi{\'n}ski, W. and Baranowski, J. M.", doi = "10.1063/1.4884015", journal = "Journal of Applied Physics", pages = 233504, title = "Nitrogen doping of chemical vapor deposition grown graphene on 4H-SiC (0001)", url = "http://dx.doi.org/10.1063/1.4884015", volume = 115, year = 2014, month = "Jun", abstract = "We present optical, electrical, and structural properties of nitrogen-doped graphene grown on the Si face of 4H-SiC (0001) by chemical vapor deposition method using propane as the carbon precursor and N2 as the nitrogen source. The incorporation of nitrogen in the carbon lattice was confirmed by X-ray photoelectron spectroscopy. Angle-resolved photoemission spectroscopy shows carrier behavior characteristic for massless Dirac fermions and confirms the presence of a graphene monolayer in the investigated nitrogen-doped samples. The structural and electronic properties of the material were investigated by Raman spectroscopy. A systematical analysis of the graphene Raman spectra, including D, G, and 2D bands, was performed. In the case of nitrogen-doped samples, an electron concentration on the order of 5–10x10^12 cm^−2 was estimated based upon Raman and Hall effect measurements and no clear dependence of the carrier concentration on nitrogen concentration used during growth was observed. This high electron concentration can be interpreted as both due to the presence of nitrogen in graphitic-like positions of the graphene lattice as well as to the interaction with the substrate. A greater intensity of the Raman D band and increased inhomogeneity, as well as decreased electron mobility, observed for nitrogen-doped samples, indicate the formation of defects and a modification of the growth process induced by nitrogen doping." }Agata Podsiadły-Paszkowska and Mariusz Krawiec.
Adsorption and diffusion of atoms on the Si(335)–Au surface.
Surface Science 622:9, April 2014.
Abstract Adsorption and diffusion of atoms (Pb, In, Ag, Na and Mg) on the Si(335)-Au surface are studied with density functional theory. Depending on the chemical species, the preferential adsorption sites of adatoms are located at step edges of the surface or in the middle of terraces, near the Au chains. The movement of atoms is strongly anisotropic and proceeds mainly in a single channel along the step edges, according to atomic hopping only. The calculated diffusion barriers are usually higher than in the case of similar Si(553)-Au surface. The differences are ascribed to a number of the Au chains on each terrace of these surfaces. URL, DOI BibTeX@article{Podsiad_y_Paszkowska_2014, author = "Podsiad{\l}y-Paszkowska, Agata and Krawiec, Mariusz", doi = "10.1016/j.susc.2013.11.016", issn = "0039-6028", journal = "Surface Science", pages = 9, publisher = "Elsevier BV", title = "Adsorption and diffusion of atoms on the Si(335)--Au surface", url = "http://dx.doi.org/10.1016/j.susc.2013.11.016", volume = 622, year = 2014, month = "Apr", abstract = "Adsorption and diffusion of atoms (Pb, In, Ag, Na and Mg) on the Si(335)-Au surface are studied with density functional theory. Depending on the chemical species, the preferential adsorption sites of adatoms are located at step edges of the surface or in the middle of terraces, near the Au chains. The movement of atoms is strongly anisotropic and proceeds mainly in a single channel along the step edges, according to atomic hopping only. The calculated diffusion barriers are usually higher than in the case of similar Si(553)-Au surface. The differences are ascribed to a number of the Au chains on each terrace of these surfaces." }P Nita, K Palotás, M Jałochowski and M Krawiec.
Surface diffusion of Pb atoms on the Si(553)-Au surface in narrow quasi-one-dimensional channels.
Phys. Rev. B 89:165426, April 2014.
Abstract The one-dimensional diffusion of individual Pb atoms on the Si(553)-Au surface has been investigated by a combination of scanning tunneling microscopy (STM), spectroscopy (STS), and first-principles density functional theory. The obtained results unambiguously prove that the diffusion channels are limited to a narrow region between Au chains and step edges of the surface. Much wider channels observed in STM and STS data have electronic origin and result from an interaction of Pb with surface atoms. The length of the channels is determined by a distance between defects at step edges of the Si(553)-Au surface. The defects can act as potential barriers or potential wells for Pb atoms, depending on their origin. URL, DOI BibTeX@article{PhysRevB.89.165426, author = "Nita, P. and Palot{\'a}s, K. and Ja{\l}ochowski, M. and Krawiec, M.", doi = "10.1103/PhysRevB.89.165426", journal = "Phys. Rev. B", pages = 165426, title = "Surface diffusion of Pb atoms on the Si(553)-Au surface in narrow quasi-one-dimensional channels", url = "https://link.aps.org/doi/10.1103/PhysRevB.89.165426", volume = 89, year = 2014, month = "Apr", abstract = "The one-dimensional diffusion of individual Pb atoms on the Si(553)-Au surface has been investigated by a combination of scanning tunneling microscopy (STM), spectroscopy (STS), and first-principles density functional theory. The obtained results unambiguously prove that the diffusion channels are limited to a narrow region between Au chains and step edges of the surface. Much wider channels observed in STM and STS data have electronic origin and result from an interaction of Pb with surface atoms. The length of the channels is determined by a distance between defects at step edges of the Si(553)-Au surface. The defects can act as potential barriers or potential wells for Pb atoms, depending on their origin." }Mariusz Krawiec.
Protecting Au-stabilized vicinal Si surfaces from degradation: Graphene on the Si(553)–Au surface.
Applied Surface Science 304:44, 2014.
Abstract We propose an efficient method of protecting the Au-induced stepped Si(553) surface from degradation when exposed to the environment. This applies to both the atomic and electronic structures, and is achieved by covering the surface with graphene. Using density functional theory we show that graphene deposited on the Si(553)-Au surface extremely weakly interacts with it, leaving its structural and electronic properties unaltered. In particular, the π-electrons of graphene are completely decoupled from electrons of the surface Au chains. At the same time, the graphene-covered Si(553)-Au surface is more resistant to the adsorption of foreign atoms, which is very promising in view of technological applications of the Au-stabilized vicinal Si surfaces. The proposed idea could be generalized to other vicinal Si surfaces. URL, DOI BibTeX@article{Krawiec_2014, author = "Krawiec, Mariusz", doi = "10.1016/j.apsusc.2013.12.141", issn = "0169-4332", journal = "Applied Surface Science", pages = 44, publisher = "Elsevier BV", title = "Protecting Au-stabilized vicinal Si surfaces from degradation: Graphene on the Si(553)--Au surface", url = "http://dx.doi.org/10.1016/j.apsusc.2013.12.141", volume = 304, year = 2014, mount = "Jun", abstract = "We propose an efficient method of protecting the Au-induced stepped Si(553) surface from degradation when exposed to the environment. This applies to both the atomic and electronic structures, and is achieved by covering the surface with graphene. Using density functional theory we show that graphene deposited on the Si(553)-Au surface extremely weakly interacts with it, leaving its structural and electronic properties unaltered. In particular, the π-electrons of graphene are completely decoupled from electrons of the surface Au chains. At the same time, the graphene-covered Si(553)-Au surface is more resistant to the adsorption of foreign atoms, which is very promising in view of technological applications of the Au-stabilized vicinal Si surfaces. The proposed idea could be generalized to other vicinal Si surfaces." }
2013
M Ślęzak, T Giela, D Wilgocka-Ślęzak, A Kozioł-Rachwał, T Ślęzak, R Zdyb, N Spiridis, C Quitmann, J Raabe, N Pilet and al..
X-ray photoemission electron microscopy study of the in-plane spin reorientation transitions in epitaxial Fe films on W(110).
Journal of Magnetism and Magnetic Materials 348:101, December 2013.
Abstract The thickness- and temperature-induced in-plane spin reorientation transitions (SRT) in epitaxial Fe films on a W(110) single crystal were investigated using X-ray photoemission electron microscopy. We present the real time evolution of the magnetisation switching, and we demonstrate differences between the two transition mechanisms. Whereas both the transitions involve the magnetic domain wall motion, the temperature SRT is additionally accompanied by nucleation of domains. Before and after the thickness-induced SRTs, the sample is in the almost single domain state, which is not the case for the final magnetic configuration after the temperature-induced transition. URL, DOI BibTeX@article{_l_zak_2013, author = "{\'S}lęzak, M. and Giela, T. and Wilgocka-{\'S}lęzak, D. and Kozio{\l}-Rachwa{\l}, A. and {\'S}lęzak, T. and Zdyb, R. and Spiridis, N. and Quitmann, C. and Raabe, J. and Pilet, N. and et al.", doi = "10.1016/j.jmmm.2013.08.024", issn = "0304-8853", journal = "Journal of Magnetism and Magnetic Materials", month = "Dec", pages = 101, publisher = "Elsevier BV", title = "X-ray photoemission electron microscopy study of the in-plane spin reorientation transitions in epitaxial Fe films on W(110)", url = "http://dx.doi.org/10.1016/j.jmmm.2013.08.024", volume = 348, x-fetchedfrom = "DOI", year = 2013, abstract = "The thickness- and temperature-induced in-plane spin reorientation transitions (SRT) in epitaxial Fe films on a W(110) single crystal were investigated using X-ray photoemission electron microscopy. We present the real time evolution of the magnetisation switching, and we demonstrate differences between the two transition mechanisms. Whereas both the transitions involve the magnetic domain wall motion, the temperature SRT is additionally accompanied by nucleation of domains. Before and after the thickness-induced SRTs, the sample is in the almost single domain state, which is not the case for the final magnetic configuration after the temperature-induced transition." }M Kopciuszyński, P Dyniec, M Krawiec, P Łukasik, M Jałochowski and R Zdyb.
Pb nanoribbons on the Si(553) surface.
Phys. Rev. B 88:155431, October 2013.
Abstract The crystallographic structure and morphology of the Si(553) surface ordered by Pb atoms are investigated with the reflection high-energy electron diffraction (RHEED), scanning tunneling microscopy (STM) and density functional theory (DFT) techniques. Adsorption of 1.3 monolayers of Pb, and a subsequent gentle annealing, causes regular distribution of Si atomic steps over the macroscopic sample area. The step periodicity is exactly the same as in the case of the Au-induced Si(553). However, the hybridization between Pb and Si atoms is weaker, as compared to Au and Si atoms on the Si(553) surface. Instead of two Au atomic chains strongly bonded to Si atoms, Pb forms a five-atom-wide nanoribbon on each Si(111) terrace. The simulated STM topography images obtained with the DFT calculations agree very well with the results obtained in the RHEED and STM experiments. URL, DOI BibTeX@article{PhysRevB.88.155431, author = "Kopciuszy{\'n}ski, M. and Dyniec, P. and Krawiec, M. and {\L}ukasik, P. and Ja{\l}ochowski, M. and Zdyb, R.", doi = "10.1103/PhysRevB.88.155431", journal = "Phys. Rev. B", month = "Oct", pages = 155431, publisher = "American Physical Society", title = "Pb nanoribbons on the Si(553) surface", url = "https://link.aps.org/doi/10.1103/PhysRevB.88.155431", volume = 88, year = 2013, abstract = "The crystallographic structure and morphology of the Si(553) surface ordered by Pb atoms are investigated with the reflection high-energy electron diffraction (RHEED), scanning tunneling microscopy (STM) and density functional theory (DFT) techniques. Adsorption of 1.3 monolayers of Pb, and a subsequent gentle annealing, causes regular distribution of Si atomic steps over the macroscopic sample area. The step periodicity is exactly the same as in the case of the Au-induced Si(553). However, the hybridization between Pb and Si atoms is weaker, as compared to Au and Si atoms on the Si(553) surface. Instead of two Au atomic chains strongly bonded to Si atoms, Pb forms a five-atom-wide nanoribbon on each Si(111) terrace. The simulated STM topography images obtained with the DFT calculations agree very well with the results obtained in the RHEED and STM experiments." }J M. Baranowski, M Mozdzonek, P Dabrowski, K Grodecki, P Osewski, W Kozlowski, M Kopciuszynski and W Strupinski.
Observation of Electron-Phonon Couplings and Fano Re-sonances in Epitaxial Bilayer Graphene.
Graphene 02:115, October 2013.
Abstract The results of optical investigation of hydrogenated epitaxial bilayer graphene are presented. A softening and an increase of the intensity of the in-plane anti-symmetric phonon mode are observed at 0.2 eV. It is suggested that they both originate from coupling of the optically active phonon mode to virtual electronic transitions, which is related to the band structure of bilayer graphene and leads to the “charged phonon” effect. In addition, it is noted that optically active phonon peaks have pronounced Fano shapelines. It is argued that the Fano shapeline is attributed to the interaction of the phonon mode with a continuum of electronic transitions in valence bands of hydrogenated bilayer graphene. URL, DOI BibTeX@article{M_Baranowski_2013, author = "{M. Baranowski}, J. and Mozdzonek, M. and Dabrowski, P. and Grodecki, K. and Osewski, P. and Kozlowski, W. and Kopciuszynski, M. and Strupinski, W.", doi = "10.4236/graphene.2013.24017", issn = "2169-3471", journal = "Graphene", month = "Oct", pages = 115, publisher = "Scientific Research Publishing, Inc,", title = "Observation of Electron-Phonon Couplings and Fano Re-sonances in Epitaxial Bilayer Graphene", url = "http://dx.doi.org/10.4236/graphene.2013.24017", volume = 02, x-fetchedfrom = "DOI", year = 2013, abstract = "The results of optical investigation of hydrogenated epitaxial bilayer graphene are presented. A softening and an increase of the intensity of the in-plane anti-symmetric phonon mode are observed at 0.2 eV. It is suggested that they both originate from coupling of the optically active phonon mode to virtual electronic transitions, which is related to the band structure of bilayer graphene and leads to the “charged phonon” effect. In addition, it is noted that optically active phonon peaks have pronounced Fano shapelines. It is argued that the Fano shapeline is attributed to the interaction of the phonon mode with a continuum of electronic transitions in valence bands of hydrogenated bilayer graphene." }T Kwapiński.
Electronic properties of a quantum wire interacting with a surface: the role of periodically placed impurities.
Journal of Physics: Condensed Matter 25:415304, September 2013.
Abstract The transmittance and density of states (DOS) of a quantum wire which is tunnel coupled to the underlying substrate are investigated theoretically using the retarded Green's function method. The wire is composed of periodically placed impurities with Coulomb interactions and is modeled by a tight-binding Hamiltonian within the mean-field approximation. For a given periodicity of impurities along the wire we observe energy gaps in the structure of DOS. These gaps disappear for a wire coupled with the substrate electrode with localized electrons which leads to a metal–insulator transition in the system. Our numerical studies reveal that the transmittance through the system strongly depends on whether or not the substrate electrons are localized. URL, DOI BibTeX@article{Kwapi_ski_2013, author = "Kwapi{\'n}ski, T", doi = "10.1088/0953-8984/25/41/415304", issn = "1361-648X", journal = "Journal of Physics: Condensed Matter", month = "Sep", pages = 415304, publisher = "IOP Publishing", title = "Electronic properties of a quantum wire interacting with a surface: the role of periodically placed impurities", url = "http://dx.doi.org/10.1088/0953-8984/25/41/415304", volume = 25, year = 2013, abstract = "The transmittance and density of states (DOS) of a quantum wire which is tunnel coupled to the underlying substrate are investigated theoretically using the retarded Green's function method. The wire is composed of periodically placed impurities with Coulomb interactions and is modeled by a tight-binding Hamiltonian within the mean-field approximation. For a given periodicity of impurities along the wire we observe energy gaps in the structure of DOS. These gaps disappear for a wire coupled with the substrate electrode with localized electrons which leads to a metal–insulator transition in the system. Our numerical studies reveal that the transmittance through the system strongly depends on whether or not the substrate electrons are localized." }R Zdyb and E Bauer.
Spin-resolved inelastic mean free path of slow electrons in Fe.
Journal of Physics: Condensed Matter 25:272201, June 2013.
Abstract The spin-dependent reflectivity of slow electrons from ultrathin Fe films on W(110) has been measured with spin polarized low energy electron microscopy. From the amplitude of the quantum size oscillations observed in the reflectivity curves the spin-dependent inelastic mean free path (IMFP) of electrons in Fe has been determined in the energy range from 5 to 16 eV above the vacuum level. The resulting IMFP values for the spin-up electrons are clearly larger than those for the spin-down electrons and the difference between the two values decreases with increasing electron energy in agreement with theoretical predictions. URL, DOI BibTeX@article{Zdyb_2013, author = "Zdyb, R and Bauer, E", doi = "10.1088/0953-8984/25/27/272201", issn = "1361-648X", journal = "Journal of Physics: Condensed Matter", month = "Jun", pages = 272201, publisher = "IOP Publishing", title = "Spin-resolved inelastic mean free path of slow electrons in Fe", url = "http://dx.doi.org/10.1088/0953-8984/25/27/272201", volume = 25, x-fetchedfrom = "DOI", year = 2013, abstract = "The spin-dependent reflectivity of slow electrons from ultrathin Fe films on W(110) has been measured with spin polarized low energy electron microscopy. From the amplitude of the quantum size oscillations observed in the reflectivity curves the spin-dependent inelastic mean free path (IMFP) of electrons in Fe has been determined in the energy range from 5 to 16 eV above the vacuum level. The resulting IMFP values for the spin-up electrons are clearly larger than those for the spin-down electrons and the difference between the two values decreases with increasing electron energy in agreement with theoretical predictions." }Qiang Wu, R Zdyb, E Bauer and M S Altman.
Growth, magnetism and ferromagnetic thickness gap in Fe films on the W(111) surface.
Phys. Rev. B 87:104410, March 2013.
Abstract The growth, structure, and magnetism of Fe films on the W(111) surface were investigated using low energy electron microscopy (LEEM) and diffraction (LEED), spin polarized LEEM (SPLEEM), and work function measurements. In contrast to an earlier report that Fe grows with fcc structure following initial pseudomorpic layer growth, we observe no evidence of the formation of fcc Fe over the entire thickness range studied, up to 18 monolayers (ML). Observations are instead consistent with the formation of a well-ordered, laterally (tensile) strained bcc Fe layer that gradually relaxes vertically and develops increasing disorder with increasing thickness. Ferromagnetic order appears at 6 ML, but surprisingly vanishes at 8 ML, and reappears just as suddenly at 9 ML during Fe deposition at room temperature. Ferromagnetism between 6 and 8 ML also vanishes at only 5 deg above room temperature. The magnetization direction of a monodomain structure remains constant before and after the ferromagnetic thickness gap at 8–9 ML until the formation of a multidomain structure at about 12 ML. Variations of exchange asymmetry in spin-polarized elastic electron scattering are also observed with increasing film thickness, particularly above 12 ML, that indicate changes in the spin-polarized electron band structure above the vacuum level. The evolution of magnetism and exchange asymmetry with increasing thickness and the appearance of the ferromagnetic gap are attributed to structural and morphological changes in the strained Fe layer, which eventually lead to a relaxed although highly disordered bcc Fe layer. URL, DOI BibTeX@article{PhysRevB.87.104410, author = "Wu, Qiang and Zdyb, R. and Bauer, E. and Altman, M. S.", doi = "10.1103/PhysRevB.87.104410", journal = "Phys. Rev. B", month = "Mar", numpages = 9, pages = 104410, publisher = "American Physical Society", title = "Growth, magnetism and ferromagnetic thickness gap in Fe films on the W(111) surface", url = "https://link.aps.org/doi/10.1103/PhysRevB.87.104410", volume = 87, year = 2013, abstract = "The growth, structure, and magnetism of Fe films on the W(111) surface were investigated using low energy electron microscopy (LEEM) and diffraction (LEED), spin polarized LEEM (SPLEEM), and work function measurements. In contrast to an earlier report that Fe grows with fcc structure following initial pseudomorpic layer growth, we observe no evidence of the formation of fcc Fe over the entire thickness range studied, up to 18 monolayers (ML). Observations are instead consistent with the formation of a well-ordered, laterally (tensile) strained bcc Fe layer that gradually relaxes vertically and develops increasing disorder with increasing thickness. Ferromagnetic order appears at 6 ML, but surprisingly vanishes at 8 ML, and reappears just as suddenly at 9 ML during Fe deposition at room temperature. Ferromagnetism between 6 and 8 ML also vanishes at only 5 deg above room temperature. The magnetization direction of a monodomain structure remains constant before and after the ferromagnetic thickness gap at 8–9 ML until the formation of a multidomain structure at about 12 ML. Variations of exchange asymmetry in spin-polarized elastic electron scattering are also observed with increasing film thickness, particularly above 12 ML, that indicate changes in the spin-polarized electron band structure above the vacuum level. The evolution of magnetism and exchange asymmetry with increasing thickness and the appearance of the ferromagnetic gap are attributed to structural and morphological changes in the strained Fe layer, which eventually lead to a relaxed although highly disordered bcc Fe layer." }Mariusz Krawiec.
Spin–orbit splitting in the Si(335)–Au surface.
Surface Science 609:44, March 2013.
Abstract Using density functional theory it is shown that spin–orbit coupling is crucial to understand and properly describe the electronic band structure of the Si(335)–Au surface. The spin–orbit splitting is responsible for the doublet of one-dimensional surface bands observed in photoemission. This suggests that the electronic bands of different gold-induced vicinal Si surfaces have similar character and are governed by the spin–orbit interaction. URL, DOI BibTeX@article{Krawiec_2013, author = "Krawiec, Mariusz", doi = "10.1016/j.susc.2012.10.024", issn = "0039-6028", journal = "Surface Science", month = "Mar", pages = 44, publisher = "Elsevier BV", title = "Spin--orbit splitting in the Si(335)--Au surface", url = "http://dx.doi.org/10.1016/j.susc.2012.10.024", volume = 609, x-fetchedfrom = "DOI", year = 2013, abstract = "Using density functional theory it is shown that spin–orbit coupling is crucial to understand and properly describe the electronic band structure of the Si(335)–Au surface. The spin–orbit splitting is responsible for the doublet of one-dimensional surface bands observed in photoemission. This suggests that the electronic bands of different gold-induced vicinal Si surfaces have similar character and are governed by the spin–orbit interaction." }R Zdyb, T O Mentes, A Locatelli, M A Niño and E Bauer.
Inelastic mean free path from reflectivity of slow electrons.
Phys. Rev. B 87:075436, February 2013.
Abstract The inelastic mean free path (IMFP) of electrons is derived using a new approach based on the low-energy electron reflectivity from ultrathin films. The thickness-dependent quantum size oscillations as a function of electron energy observed in the reflectivity of slow electrons are modeled using an absorbing Fabry-Pérot interferometer consisting of vacuum, film, and substrate. The absorbing properties of the film are represented by the imaginary part of the complex refractive index associated with the IMFP which determines the amplitude of the electron reflectivity oscillations. Using this formalism for an Fe film on W(110), the IMFP in Fe is found in the energy range from 4 to 18 eV above the vacuum level. In contrast to the common notion, the IMFP in Fe is shown to have a very weak energy dependence at low energy. The results are in good agreement with independent IMFP measurements found in thickness-dependent photoemission experiments. URL, DOI BibTeX@article{PhysRevB.87.075436, author = "Zdyb, R. and Mentes, T. O. and Locatelli, A. and Ni\~no, M. A. and Bauer, E.", doi = "10.1103/PhysRevB.87.075436", journal = "Phys. Rev. B", month = "Feb", pages = 075436, publisher = "American Physical Society", title = "Inelastic mean free path from reflectivity of slow electrons", url = "https://link.aps.org/doi/10.1103/PhysRevB.87.075436", volume = 87, year = 2013, abstract = "The inelastic mean free path (IMFP) of electrons is derived using a new approach based on the low-energy electron reflectivity from ultrathin films. The thickness-dependent quantum size oscillations as a function of electron energy observed in the reflectivity of slow electrons are modeled using an absorbing Fabry-Pérot interferometer consisting of vacuum, film, and substrate. The absorbing properties of the film are represented by the imaginary part of the complex refractive index associated with the IMFP which determines the amplitude of the electron reflectivity oscillations. Using this formalism for an Fe film on W(110), the IMFP in Fe is found in the energy range from 4 to 18 eV above the vacuum level. In contrast to the common notion, the IMFP in Fe is shown to have a very weak energy dependence at low energy. The results are in good agreement with independent IMFP measurements found in thickness-dependent photoemission experiments." }M Krawiec and M Jałochowski.
Anisotropic atom diffusion on Si(553)-Au surface.
Phys. Rev. B 87:075445, February 2013.
Abstract Using density functional theory, we study atomic diffusion on the Si(553)-Au surface. We have calculated the potential energy surfaces for atoms of different chemical elements (Ag, Au, Mg, In, and Si). By tracing the adatom positions and the energetics of a fully relaxed surface, we have calculated energy barriers, diffusion paths, and hopping rates along and across the steps. The results show that in most cases, the surface diffusion is strongly anisotropic, while the energy barriers and hopping rates have a strong dependency on the chemical species of the adatom. In the case of Au, Ag, and Mg atoms, the diffusion can be realized in two separate one-dimensional channels, featuring different mechanisms of the diffusion. URL, DOI BibTeX@article{PhysRevB.87.075445, author = "Krawiec, M. and Ja{\l}ochowski, M.", doi = "10.1103/PhysRevB.87.075445", issue = 7, journal = "Phys. Rev. B", month = "Feb", numpages = 8, pages = 075445, publisher = "American Physical Society", title = "Anisotropic atom diffusion on Si(553)-Au surface", url = "https://link.aps.org/doi/10.1103/PhysRevB.87.075445", volume = 87, year = 2013, abstract = "Using density functional theory, we study atomic diffusion on the Si(553)-Au surface. We have calculated the potential energy surfaces for atoms of different chemical elements (Ag, Au, Mg, In, and Si). By tracing the adatom positions and the energetics of a fully relaxed surface, we have calculated energy barriers, diffusion paths, and hopping rates along and across the steps. The results show that in most cases, the surface diffusion is strongly anisotropic, while the energy barriers and hopping rates have a strong dependency on the chemical species of the adatom. In the case of Au, Ag, and Mg atoms, the diffusion can be realized in two separate one-dimensional channels, featuring different mechanisms of the diffusion." }R Taranko and T Kwapiński.
Dynamics of a charge qubit coupled with a double-dot detector.
Physica E: Low-dimensional Systems and Nanostructures 48:157, February 2013.
Abstract We investigate theoretically the dynamics of a charge qubit (double quantum dot system) coupled electrostatically with the double-dot detector. The qubit charge oscillations and the detector current are calculated using the equation of motion method for appropriate correlation functions. In order to find the best detector performance (i.e. the detector current signal follows as well as possible the qubit charge oscillations) we consider different qubit-detector geometries. The optimal setup was found for the qubit lying parallel to the detector quantum dots for which we observed very good detector performance together with weak decoherence of the system. It is also shown that the asymptotic detector current (flowing in response to the limited in time qubit-detector interaction) fully reproduces the qubit dynamics. URL, DOI BibTeX@article{Taranko_2013, author = "Taranko, R. and Kwapi{\'n}ski, T.", doi = "10.1016/j.physe.2012.12.012", issn = "1386-9477", month = "Feb", pages = 157, publisher = "Elsevier BV", journal = "Physica E: Low-dimensional Systems and Nanostructures", title = "Dynamics of a charge qubit coupled with a double-dot detector", url = "http://dx.doi.org/10.1016/j.physe.2012.12.012", volume = 48, x-fetchedfrom = "DOI", year = 2013, abstract = "We investigate theoretically the dynamics of a charge qubit (double quantum dot system) coupled electrostatically with the double-dot detector. The qubit charge oscillations and the detector current are calculated using the equation of motion method for appropriate correlation functions. In order to find the best detector performance (i.e. the detector current signal follows as well as possible the qubit charge oscillations) we consider different qubit-detector geometries. The optimal setup was found for the qubit lying parallel to the detector quantum dots for which we observed very good detector performance together with weak decoherence of the system. It is also shown that the asymptotic detector current (flowing in response to the limited in time qubit-detector interaction) fully reproduces the qubit dynamics." }
2012 and before
A. Stępniak, M. Krawiec, G. Zawadzki, M. Jałochowski, Electronic stabilization of the Si(111)5 x 2-Au surface: Pb and Si adatoms, J. of Phys: Cond. Matter, 24, 095002 (2012).
T. Kwapiński, R. Taranko, Quantum wire as a charge-qubit detector, Phys. Rev. A86,052338 (2012).
T. Kwapiński, Phase-dependent electron transport through a quantum wire on a surface, J. of Phys: Cond. Matter, 24, 055302 (2012).
P. Nita, M. Jałochowski, M. Krawiec, A. Stępniak, One-dimensional diffusion of Pb atoms on the Si(553)-Au surface, Phys. Rev. Lett. 107, 026101 (2011).
P. Nita, G. Zawadzki, M. Krawiec, M. Jałochowski, Structural and electronic properties of double Pb chains on the Si(553)-Au surface, Phys. Rev. B84, 085453 (2011).
T. Kwapiński, R. Taranko, Spin and charge pumping in a quantum wire: the role of spin-flipscattering and Zeeman splitting, J. of Phys: Cond. Matter, 23, 405301 (2011).
T. Kwapiński, S. Kohler and P.Hanggi, Dynamically broken symmetry in periodically gated quantum dots: Charge accumulation and dc-current, Ukr. J. Phys. 55, 85 (2010).
Z. Korczak, T. Kwapiński, P Mazurek, Conductance of Pb on modified Si(335) vicinal surface, Surf. Sci., 604, 54 (2010).
M. Krawiec, Structural model of the Au-induced Si(553) surface: Double Au rows, Phys. Rev. B81,115436 (2010).
M. Krawiec, M. Jałochowski, Doping of the step-edge Si chain: Ag on a Si(557)-Au surface, Phys. Rev. B82, 195443 (2010).
T. Kwapiński and M. Jałochowski, Signature of tip electronic states on tunneling spectra, Surf. Sci. 604, 1752 (2010).
M. Krawiec, M. Jałochowski, Array of double Au-Ag chains on the Si(557) surface, Appl. Surf. Sci. 256, 4813 (2010).
T. Kwapiński,Tip apex charged states in tunneling spectroscopy, Physica, E43, 333 (2010).
T. Kwapiński, S. Kohler and P. Hanggi, Electron transport across a quantum wire in the presence of electron leakage to a substrate, Eur. Phys. J. B78, 75 (2010).
T. Kwapiński, Conductance oscillations and charge waves in zigzag shaped quantum wires, J. Phys: Cond. Matter, 22, 295303. (2010).
M. Krawiec, Pb chains on reconstructed Si(335) surface, Phys. Rev. B79, 155438 (2009).
A. Stępniak, P. Nita, M. Krawiec, M. Jałochowski, In and Si adatoms on Si(111)5x2-Au: Scanning tunneling microscopy and first-principles density functional calculations, Phys. Rev. B80, 125430 (2009).
R. Zdyb, T. O. Mentes, A. Locatelli, M. A. Nino, and E. Bauer, Magnetization and structure of ultrathin Fe films, Phys. Rev. B80,184425 (2009).
T. Kwapinski, S. Kohler, P. Hanggi, Discontinuous conductance of bichromatically ac-gatted quantum wires, Phys. Rev. B79, 155315 (2009).
R. Zdyb, A. Pavlovska, E. Bauer, Strain engineering of magnetic anisotropy in thin ferromagnetic films, J. Phys: Condens. Matter, 21, 314012 (2009).
Hoang Vu Chung, Markus Klevenz, Robert Lovrincic, Frank Neubrech, Olaf Skibbe, Annemarie Pucci, Pawel Nita, Mieczyslaw Jalochowski, and Tadaaki Nagao, Studies on gold atom chains and lead nanowires on silicon vicinal surfaces, Journal of Physics: Conf. Series 187, 012025 (2009).
M. Krawiec, Thermoelectric transport through a quantum dot coupled to a normal metal and BCS superconductor, Acta Phys. Pol., A114, 115 (2008).
M. Klevenz, F. Neubrech, R. Lovrincic, M. Jałochowski,
and A. Pucci, Infrared resonances of self-assembled Pb nanorods, Appl. Phys. Lett., 92, 133116 (2008).
M. Krawiec, First principles study of Si(335)-Au surface, Appl. Surf. Sci., 254, 4318 (2008).
R. Zdyb, Influence of substarte morphology on Pb growth, Appl. Surf. Sci., 254, 4408 (2008).
M. Kisiel, K. Skrobas, M. Jałochowski, Photoelectron diffraction effect In the highly ordered Si(557)/Pb surface, Appl. Surf. Sci. 254, 4313 (2008).
R. Zdyb, Growth of Pb on Si(335) surface, J. of Non-Crystall. Solid, 354, 4176 (2008).
K. Skrobas, R. Zdyb, M. Kisiel, M. Jałochowski, Band structure of In chains on Si(335)-Au,Materials Science-Poland, 26, 55 (2008).
L. Douillard, F. Charra, Z. Korczak, R. Bachelot, S. Kostcheev, G. Lerondel, P.-M. Adam, and P. Royer, Short Range Plasmon Resonators Probed by Photoemission Electron Microscopy, Nano Letters, 8, 935 (2008).
T. Kwapiński, M. Krawiec, M. Jałochowski, STM tunneling through a quantum wire with a side-attached impurity, Phys. Lett. A372, 154 (2008).
R. Zdyb, E. Bauer, Coexistence of ferromagnetism and paramagnetism in a ferromagnetic monolayer, Phys. Rev. Lett., 100, 155704 (2008).
M. Krawiec, K. I. Wysokiński, Thermoelectric phenomena in a quantum dot asymmetrically coupled to external leads, Phys. Rev, B75, 155330 (2007).
M. C. Tringides, M. Jalochowski, E. Bauer, Quantum size effects in metallic nanostructures,, Physics Today 50, April (2007).
Z. Korczak T. Kwapiński, Electrical conductance at initial stage In epitaxial growth of Pb, Ag, Au and In on modified Si(111) surface, Surf. Sci. 601, 3324 (2007).
M. Krawiec, M. Jałochowski, Thermoelectric effects in STM tunneling through a monoatomic chain, phys. stat. sol. (b), 244, 2464 (2007).
A. Gorczyca, M. Krawiec, M. M. Maśka, M. Mierzejewski, Particle-hole asymmetry in the scanning tunneling spectroscopy of the high temperature superconductors, phys. stat. sol. (b), 244, 2448 (2007).
M. Krawiec, Compensation of the Kondo effect in quantum dots coupled to ferromagnetic leads within the equation of motion approach, J. Phys: Condensed Matter, 19, 346234 (2007).
Journal of Physics: Condensed Matter, T. Kwapiński, Conductance oscillations of a quantum wire disturbed by an adatom, J. Phys: Condensed Matter, 19, 176218 (2007).
G. Litak, M. Krawiec, Properties of the pi state induced by impurities in a d-wave superconductor, Physica C460, 1066 (2007).
M. Kisiel, K. Skrobas, R. Zdyb, P. Mazurek, M. Jałochowski, Pb chains on ordered Si(335) surface, Phys. Lett. A364, 152 (2007).
K. Skrobas, R. Zdyb, M. Kisiel, M. Jałochowski, Band structure of In chains on Si(335)-Au, Materials Science, 25 (2007),
B. Pawlikowska-Pawlęga, W. I. Gruszecki, L. E. Misiak, R. Paduch, T. Piersiak, B. Zarzycka, J. Pawelec, A. Gawron, Modification of membranes by quercetin, a naturally occurring flawonoid, via its incorporation in the polar head group, Biochimica et Biophysica Acta ?Biomembranes (Biochim. Biophys. Acta), 1768, 2195 (2007).
M. Krawiec, K. I. Wysokiński, Thermoelectric effects in strongly interacting quantum dot coupled to ferromagnetic leads, Phys. Rev, B73, 075307 (2006).
M. Krawiec, T. Kwapiński, M. Jałochowski, Double nonequivalent chain structure on a vicinal Si(557)-Au surface, Phys. Rev, B73, 075415 (2006).
Annemarie Pucci, Florian Kost, Gerhard Fahsold, Mieczyslaw Jałochowski, Infrared spectroscopy of Pb layer growth on Si(111), Phys. Rev, B74, 125428 (2006).
M. Krawiec, M. Jałochowski, M. Kisiel, High resolution scanning tunneling spectroscopy of ultrathin Pb on Si(111)-(6x6) substrate, Surf. Sci, 600, 1641 (2006).
M. Krawiec, T. Kwapiński, Electron transport through a strongly correlated monoatomic chain, Surf. Sci, 600, 1697 (2006).
Z. Korczak and T. Kwapiński, Electrical conductance at initial stage in epitaxial growth of Pb on modified Si(111) surface, Surf. Sci, 600, 1650 (2006).
R. Zdyb, A. Pavlovska, M. Jałochowski, E. Bauer, Self-organized Fe nanostructures on W(110), Surf. Sci, 600, 1586 (2006).
M. Krawiec, J. F. Annett, B. L. Gyorffy, Spontaneous currents in a ferromagnet ?normal metal ?superconducting trilayer, Acta. Phys. Pol, A109, 507 (2006).
G. Litak, M. Krawiec, Superconducting pairing amplitude and local density of states in presence of repulsive centers, Physica, B 378-380, 434 (2006).
M. Krawiec, K. I. Wysokiński, Thermoelectric effects in strongly interacting quantum dot coupled to ferromagnetic leads, Physica, B 378-380, 933 (2006).
J. F. Annett, M. Krawiec, B. L. Gyorffy, Origin of spontaneous currents in a superconductor ?ferromagnet proximity system, Physica, C437-438, 7 (2006).
M. Krawiec, Residual Kondo effect in quantum dot coupled to half-metallic ferromagnets, J. Phys: Condensed Matter, 18, 6923 (2006).
T. Kwapiński, Charge fluctuations in a perfect and disturbed quantum wire, J. Phys.: Condensed Matter, 18, 7313-7326 (2006).
M. Kisiel, M. Jałochowski, R. Zdyb, Morphology and electronic structure of submonolayer Pb on Si(111)-(6x6)Au, Phys. Lett, A357, 141 (2006).
E. Bauer, R. Belkhou, S. Cherifi, R. Hertel, S. Heun, A. Locatelli, A. Pavlovska, R. Zdyb, N. Agarwal and H. Wang, Microscopy of mesoscopic ferromagnetic systems with slow electrons, Surf. and Interf. Analysis, 38, 1622 (2006).
P. Mazurek, K. Paprocki, and Z. Mitura, Investigation of Si-Au vicinal surfaces using scanning tunneling microscopy and reflection high-energy electron diffraction, J. of Microscopy, 224, 125-127 (2006).
A. Daniluk, K. Skrobas, A new version of a computer program for dynamical calculations of RHEED intensity oscillations, Comp. Phys. Communications, 174, 83-85 (2006).
M. Krawiec, T. Kwapiński, M. Jałochowski, Scanning tunneling microscopy of monoatomic gold chains on vicinal Si(335) surface: experimental and theoretical study, phys. stat. sol. (b) 242, 332 (2005).
G. Litak, M. Krawiec, pi-state?induced by impurities with a repulsive interaction, phys. stat. sol, (b) 242, 438 (2005).
T. Kwapiński, Conductance oscillations of a metallic quantum wire, J. Phys.: Condens. Matter, 17, 5849 (2005).
T. Kwapinski, R. Taranko, and E. Taranko, Photon-assisted electron transport through a three-terminal quantum dot system with nonresonant tunneling channels, Phys. Rev. B72,125312 (2005).
R. Zdyb, A. Locatelli, S. Heun, S. Cherifi, R. Belkhou, E. Bauer, Nanomagnetism Studies with Spin-Polarized Low energy Electron Microscopy and X-ray magnetic Circular Dichroism Photo Emission Electron Microscopy, Surface and Interface Analysis, 37, 239 (2005).
R. Zdyb, A. Pavlovska, A. Locatelli, S. Heun, S. Cherifi, R. Belkhou, Imaging low-dimensional magnetism with slow electrons, Applied Surface Science, 249, 38 (2005).
M. Kisiel, K. Skrobas, R. Zdyb, M. Jałochowski, Band structure of Au monoatomic chains on Si(335) and Si(557) surfaces, Optica Applicata, XXXV, No3 (2005).
M. Kisiel, K. Skrobas, M. Jałochowski, Angle-resolved photoemission of ultrathin Pb films on Si(111)-(6x6)Au: quantum size effect, Optica Applicata, XXXV, No.3 (2005).
Sujak A, Gabrielska J, Milanowska J, Mazurek P, Strzalka K, Gruszecki WI. Studies on canthaxanthin in lipid membranes, Biochemica et Biophysica Acta-Biomembranes, 17, 1712 (2005).
R.Taranko, T.Kwapiński, and E.Taranko, Influence of microwave fields on electron transport through a quantum dot in the presence of direct tunneling between leads Phys. Rev. B69, 165306 (2004).
T. Kwapiński, Time-dependent electron transport through a quantum wire, Phys. Rev. B69, 153303 (2004).
T. Kwapiński, Electron transport through a few atom system, Vacuum 74, 201 (2004).
R. Zdyb, M. Jałochowski, M. Stróżak, Quantum size effect in absorption of low energy electrons in Pb layers, Vacuum 74, 217 (2004).
M. Stróżak, V. Hnatyuk, M. Jałochowski, Optical properties of Pb nanowires on Si(335),Vacuum 74, 241 (2004).
M. Jałochowski, M. Stróżak, R. Zdyb, Optical recognition of structural and electronic transformation of Pb ultrathin films, J. Phys.: Condens. Matter, 16, S4345 (2004).
M. Krawiec, B. L. Gyorffy, J. F. Annett, Current-carrying Andreev bound states in a superconductor-ferromagnet proximity system, Phys. Rev. B70,134519 (2004).
P. Mazurek, A Daniluk, K. Paprocki, Substrate temperature control from RHEED intensity measurement, Vacuum, 72, 363 (2004).
M. L. Paradowski, L. E. Misiak, Gd3+- RE3+ exchange interactions in rare-earth fluoride crystals (RE = Ce, Nd, Yb), Acta Phys.Pol., A105, 445 (2004).
M. Jałochowski, M. Stróżak, R. Zdyb, Reflectance anisotropy during growth of Pb nanowires on well ordered Si(335) surface, Appl. Surf. Sci. 211, 209 (2003).
N. Kuroiwa, Y. Fukushima, P. Rejasekar, H. Neddermeyer, M. Jalochowski, E. Bauer, T. Yasue, T. Koshikawa, Copper nanostructure formation and structure analysis on hydrogen-terminated Si(111) surface, Surface and Interface Analysis 35, 24 (2003).
R. Zdyb, E. Bauer, Magnetic domain structure and spin reorientation transition in ultrathin Fe-Co alloy films, Phys. Rev. B67, 134420 (2003).
K. L. Man, R. Zdyb, S. F. Huang, T. C. Leung, C. T. Chan, E. Bauer, and M. S. Altman, Growth morphology, structure, and magnetism of ultrathin Co films on W(111), Phys. Rev. B67, 184402 (2003).
T.Kwapiński, R.Taranko, Time-dependent transport through a quantum dot with the over-dot (bridge) additional tunnelling channel, Physica E18, 402 (2003).
B. Pawlikowska-Pawlęga, W. I. Gruszecki, L. E. Misiak, and A. Gawron, The study of the quercetin action on human erythrocyte membranes, Biochem Pharmacol. 66, 605 (2003).
M. Krawiec, B. L. Gyorffy, J. F. Annett, Andreev bound states in ferromagnet-superconductor nanostructures, Physica, C387, 7 (2003).
M. Krawiec, B. L. Gyorffy, J. F. Annett, Spin polarized current in the ground state of superconductor-ferromagnet-insulator trilayers, European Physical Journal B32, 163 (2003).
M. Jałochowski, Si(111)-(6x6)Au surface morphology and nucleation of Pb at low temperature, Progr. Surf. Sci. 74, 97 (2003).
P. Mazurek, M. Jałochowski, Ordering of the vicinal Si(1510) surface at low Au coverages, Optica Applicata, vol. XXXII, 247 (2002).
M. Jałochowski, M. Stróżak, Optical anisotropy of Pb nanowires on Si(533) surface, Optica Applicata, vol. XXXII, 373 (2002).
M. Jałochowski, M. Stróżak, R. Zdyb, Anomalous optical absorption in ultrathin Pb films,Phys. Rev. B66, 205417 (2002).
R. Zdyb, Bauer, Spin-resolved unoccupied electronic band structure from quantum size oscillations in the reflectivity of slow electrons from ultrathin ferromagnetic crystals, Phys. Rev. Lett. 88, 166403 (2002).
R. Zdyb, E. Bauer, Spin-dependent quantum size effects in the electron reflectivity of ultrathin ferromagnetic crystals, Surf. Review and Letters 9, 1485 (2002).
E. Bauer, T. Duden, R. Zdyb, Spin-polarized low energy electron microscopy of ferromagnetic thin films, J. Phys. D: Appl. Phys. 35, 2327 (2002).
E. Jartych, M. Jałochowski, M. Budzyński, Influence of the electrodeposition parameters on surface morphology and local magnetic properties of thin iron layers, Appl. Surf. Sci., 193, 210 (2002).
M.L. Paradowski and L.E. Misiak, Gd3+ Spin-Phonon Interactions in Rare-Earth FluorideCrystals, Acta Phys. Polonica A102, 373 (2002).
A. Rysak, S. Z.Korczak, Nonlinear AC magnetic response of the Hg1223 powder, Physica C337, 217 (2002).
T. Yasue, T. Koshikawa, M. Jałochowski, E. Bauer, Dynamic Observation of the Formation of Thin Cu Layers on Clean and Hydrogen-Terminated Si(111) Surfaces, Surf. Sci. 480, 118 (2001).
R. Zdyb, M. Stróżak, M. Jałochowski, Gold-Induced Faceting on Si(533) Surface Studied by RHEED, Vacuum, 63, 107 (2001).
M. Jałochowski, E. Bauer, Growth of Metallic Nanowires on Anisotropic Si Substrates: Pb on Si(110), Vicinal Si(100), Si(755), and Si(533), Surf. Sci. 480, 109 (2001).
M. Jałochowski, E. Bauer, Self-Assembled Parallel Mesoscopic Pb-Wires on Au-Modified Si(533) Substrates, Progr. Surf. Sci. 67, 79 (2001).
E. Jartych, D. Chocyk, M. Budzyński, M. Jałochowski, Surface morphololgy and local magnetic properties of electrodeposited thin iron layers, Appl. Surf. Sci. 180, 246 (2001).
R. Zdyb, M. Stróżak, M. Jałochowski, Gold-induced faceting on Si(533) surface studied by RHEED, Vacuum 63, 107 (2001).
M. Jałochowski, E. Bauer, Growth of Metallic Nanowires on Anisotropic Si Substrates: Pb on Si(110), Vicinal Si(100), Si(755), and Si(533), Surf. Sci. 480, 109 (2001).
Th. Duden, R. Zdyb, M.S. Altman, E. Bauer, Micromagnetic and microcrystalline structure of ultrathin Co layers on W single crystal surfaces, Surf. Sci. 480, 145 (2001).
M.L. Paradowski, L.E. Misiak, W. Korczak, and Z. Korczak, Crystal field study of Gd3+-doped LaxRE1-xF3 (RE = Ce, Pr, Nd) single crystals, in International Conference on Solid State Crystals 2000: Growth, Characterization, and Applications of Single Crystals, A. Rogalski, K. Adamiec, P. Madejczyk, Editors, Proceedings of SPIE, 4412, p. 242-245 (2001), Published by SPIE (Washington, USA).
M.L. Paradowski, M. Kulik, W. Korczak and Z. Korczak, PIXE and magnetic investigations of LaxRE1-xF3 (RE = Ce, Nd) single crystals, in International Conference on Solid State Crystals 2000: Growth, Characterization, and Applications of Single Crystals, A. Rogalski, K. Adamiec, P. Madejczyk, Editors, Proceedings of SPIE, 4412, p. 246-249 (2001), Published by SPIE (Washington, USA).
E. Bauer, Th. Duden, A. Pavlovska, Th. Schmidt, R. Zdyb, Low Energy Electron Microscopy without and with Spin, Proceedings of the 6th International Symposium on Advanced Physical Fields: Growth of Well-Defined Nanostructures, (2001).
A. Rysak, Z. Korczak, Non-linear Magnetization in HTS Isolated System, Mol. Phys. Rep., 34/1, 136 (2001).
A. Rysak, S. Z. Korczak, “Vector description of nonlinear magnetization, J. Mag. Mag. Mat. 231, 323 (2001).
J. Podleśny, L. Misiak, and R. Koper, Concentration of free radicals in faba bean seeds after the pre-sowing treatment of the seeds with laser light, Int. Agrophysics 15, 185 (2001).
L.E. Misiak, Gd3+-Yb3+ exchange interactions in LiY1-xYbxF4 single crystals, in International Conference on Solid State Crystals 2000: Growth, Characterization, and Applications of Single Crystals, A. Rogalski, K. Adamiec, P. Madejczyk, Editors, Proceedings of SPIE Vol. 4412, 177 (2001).
M. Jałochowski, Mesoscopic Pb Wires on Ordered Vicinal Si(111), Electron Technology, 33, 375 (2000).
M. Jałochowski, Self-Assembled Parallel Mesoscopic Pb Wires on Vicinal Si(111), Acta Phys. Polonica, 98, 259 (2000).
T. Yasue, T. Koshikawa, M. Jałochowski, E. Bauer, Dynamic LEEM Observation of Cu Nanostructure Formation Processes on Si(111) with Hydrogen, Surf. Review Lettres, 7, 595 (2000).
T. Yasue, T. Koshikawa, M. Jałochowski, E. Bauer, Dynamic LEEM Observation of Cu Nanostructure Formation Processes on Si(111) with and without Hydrogen, Inst. Phys. Conf. Ser. 165, 259 (2000).
R. Zdyb, M. Stróżak, M. Jałochowski, Growth of the Ultra-Thin Pb Layers on Si(533) Surfaces, Electron Technology 33, 380 (2000).
M.L. Paradowski, A.W. Pacyna, A. Bombik, W. Korczak, S.Z. Korczak,Magnetic susceptibility of LaxCe1-xF3 single crystals, Journal of Magnetism and Magnetic Materials,212, 381 (2000).
Selected publications before 1998
M. Jałochowski, M. Stróżak, R. Zdyb, One-dimensional structures on Si(111) observed by RHEED, Thin Solid Films 306, 224 (1997).
M. Jałochowski, M. Stróżak, R. Zdyb, Gold-induced one-dimensional ordering on vicinal Si(111), Vacuum 48, 273 (1997).
M. Jałochowski, M. Stróżak, R. Zdyb, Gold-induced ordering on vicinal Si(111), Surf. Sci. 375, 203 (1997).
S.K. Misra and L. E. Misiak, EPR study of Gd3+- doped RbR(SO4)2 4H2O (R=Pr, Nd, Sm, Eu) single crystals: Phase transitions and spin-Hamiltonian parameters Phys. Rev. B56, 2391-2398 (1997).
M. Jałochowski, M. Hoffmann, E. Bauer, Quantized Hall Effect in Ultrathin Metallic Films,Phys. Rev. Lett, 76, 4227 (1996).
M. Jałochowski, M. Hoffmann, Pb layer-by-layer growth at very low temperatures, Phys. Rev. B51, 7231 (1995).
S. K. Misra, L. E. Misiak and P. Chand, Variable temperature EPR study of a Ni2CdCl612H2O single crystal , Physica B202, 31-40 (1994).
S. K. Misra, L. E. Misiak and J. A. Capobianco, An EPR study of a single crystal of the solid-state-laser material Mn5+-doped Sr5(PO4)3Cl , J. Phys.: Condens. Matter 6, 3955-3963 (1994).
S. K. Misra and L. E. Misiak, Electron-paramagnetic-resonance study of Cu2+-and Mn2+-doped LiCsSO4 single crystals: LiCsSO4 phase transitions, Phys. Rev. B48, 13579-13587 (1993).
M. Jałochowski, H. Knoppe, G. Lilienkamp, E. Bauer, Photoemission from Ultrathin Metallic Films: Quantum Size Effect, Electron Scattering, and Film Structure, Phys. Rev. B46, 4693 (1992).
M. Jałochowski, E, Bauer, H. Knoppe, G. Lilienkamp, Experimental evidence for quantum-size-effect fine structures in the resistivity of ultrathin Pb and Ob-In films, Phys. Rev. B45, 13607 (1992).
Z. Mitura, M.Stróżak and M. Jałochowski, RHEED Intensity Oscillations with Extra Maxima, Surf. Sci. Lett. 276, L15 (1992).
L. E. Misiak and M. Subotowicz, Temperature EPR study of LiY1-xYbxF4(Gd3+) single crystals , Solid State Commun. 80, 761-766 (1991).
S. K. Misra and L. E. Misiak, Electron paramagnetic resonance of the high-Tc superconductor Y0.9Er0.1Ba1.9Sr0.1Cu3O7- Solid State Commun.72, 117-123 (1989).
S. K. Misra, L. E. Misiak, D. Bahadur, V. Srinivas and R. A. Dunlap, Ferromagnetic resonance study of icosahedral and amorphous Al55Mn20Si25 alloys , Phys. Rev. B40, 7537-7541 (1989).
L. E. Misiak, S. K. Misra and P. Mikołajczak, EPR of Gd3+-doped single crystals of LiY1-xYbxF4, Phys. Rev. B38, 8673-8682 (1988).
M. Jałochowski, E. Bauer, Quantum size and surface effects in fhe electrical resistivity and high-energy electron reflectivity of ultrathin lead films, , Phys. Rev. B38, 5272 (1988).
M. Jałochowski, E. Bauer , Resistance oscillations and crossover in ultrathin gold films,Phys. Rev. B37, 8622 (1988).
M. Jałochowski, E.Bauer, Reflection high-energy electron diffraction intensity oscillations during the growth of Pb on Si(111), J. Appl. Phys. 63, 4501 (1988)