Physics and Astronomy › Atomic and Molecular Physics, and Optics

Surface and Thin Film Phenomena

Works Count: 46683

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Description

This cluster of papers explores the influence of quantum size effects on the electronic and superconducting properties of metallic nanostructures, particularly focusing on thin films, surface states, and atomic chains. The research delves into phenomena such as quantum well states, electron-phonon interactions, and the manifestation of superconductivity at the quantum limit.

Keywords

Superconductivity; Quantum Size Effects; Thin Films; Surface States; Electronic Structure; Metallic Nanostructures; Atomic Chains; Quantum Well States; Electron-Phonon Interaction; Scanning Tunneling Microscopy

Calculated Electronic Properties of Metals

1978-01-01

V. L. Moruzzi , J. F. Janak , A. R. Williams

The Monte Carlo Method for Semiconductor Device Simulation

1989-01-01

Carlo Jacoboni , P. Lugli

Materials Science of Thin Films

2002-01-01

Milton Ohring

Fundamentals of Semiconductors

1996-01-01

Peter Y. Yu , M. Cardona

One-dimensional dislocations. I. Static theory

1949-08-15

F. C. Frank , J. H. van der Merwe

The theory of a one-dimensional dislocation model is developed. Besides acting as a pointer to developments of general dislocation theory, it has a variety of direct physical applications, particularly to … The theory of a one-dimensional dislocation model is developed. Besides acting as a pointer to developments of general dislocation theory, it has a variety of direct physical applications, particularly to monolayers on a crystalline substrate and to conditions in the edge row of a terrace of molecules in a growing crystal. Allowance is made in the theory for a difference in natural lattice-spacing between the surface layer or row and the substrate. The form and energy of single dislocations and of regular sequences of dislocations are calculated. Critical conditions for spontaneous generation (or escape) of dislocations are determined, and likewise the activation energies for such processes below the critical limits. Various physical applications of the model are discussed, and the physical parameters are evaluated with the aid of the Lennard-Jones force law for the above-mentioned principal applications.

Optical properties of fourteen metals in the infrared and far infrared: Al, Co, Cu, Au, Fe, Pb, Mo, Ni, Pd, Pt, Ag, Ti, V, and W

1985-12-15

Mark A. Ordal , Robert J. Bell , R. W. Alexander +2 more

Infrared optical constants collected from the literature are tabulated for Mo and V. New data are presented for Cu, Fe, and Ni. Drude model parameters ωτ and ωp are given … Infrared optical constants collected from the literature are tabulated for Mo and V. New data are presented for Cu, Fe, and Ni. Drude model parameters ωτ and ωp are given for the fourteen metals Al, Co, Cu, Au, Fe, Pb, Mo, Ni, Pd, Pt, Ag, Ti, V, and W. The Drude model parameters for Cu are revised from our earlier tabulation due to the availability of additional data. Refinements in our fitting technique have resulted in only slight changes in the Drude model parameters for Al, Au, Ag, and W. The Drude model parameters for Pb correct a numerical error in our earlier tabulation. For all fourteen metals, the optical resistivity has been calculated from the Drude model parameters ωτ and ωp and compared to handbook values for the dc resistivity.

Imaging standing waves in a two-dimensional electron gas

1993-06-01

Michael F. Crommie , Christopher P. Lutz , D. M. Eigler

A well-behaved electrostatic potential based method using charge restraints for deriving atomic charges: the RESP model

1993-10-01

Christopher I. Bayly , Piotr Cieplak , Wendy D. Cornell +1 more

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA well-behaved electrostatic potential based method using charge restraints for deriving atomic charges: the RESP modelChristopher I. Bayly, Piotr Cieplak, Wendy Cornell, and Peter A. KollmanCite this: … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA well-behaved electrostatic potential based method using charge restraints for deriving atomic charges: the RESP modelChristopher I. Bayly, Piotr Cieplak, Wendy Cornell, and Peter A. KollmanCite this: J. Phys. Chem. 1993, 97, 40, 10269–10280Publication Date (Print):October 1, 1993Publication History Published online1 May 2002Published inissue 1 October 1993https://pubs.acs.org/doi/10.1021/j100142a004https://doi.org/10.1021/j100142a004research-articleACS PublicationsRequest reuse permissionsArticle Views12411Altmetric-Citations6126LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

Electrochemical aspects of the generation of ramified metallic electrodeposits

1990-12-01

J.‐N. Chazalviel

The growth of ramified metallic deposits by electrodeposition from dilute salt solutions and in a high electric field has been considered in the geometry of a thin rectangular cell. The … The growth of ramified metallic deposits by electrodeposition from dilute salt solutions and in a high electric field has been considered in the geometry of a thin rectangular cell. The equations governing ion motion in the case of a dilute electrolyte have been solved numerically and analytically in a one-dimensional (1D) and a 2D approximation. It is found that ramified growth is a direct consequence of the creation of a space charge upon anion depletion in the vicinity of the cathode. The front of the ramified deposit is predicted to advance at a speed just equal to the velocity of the anions in the applied electric field. The presence of this space charge ahead of the growing front is associated with a potential drop \ensuremath{\delta}V. Resolution of the equations in the 2D case shows that the dense-parallel morphology of the deposit also results quite naturally from the existence of a space charge in the vicinity of the filament tips. The average filament spacing and sidebranch tilting angle can be directly related to the values of \ensuremath{\delta}V and of the applied electric field. The mechanism giving rise to the space charge will apply as well to any physical system involving electric conduction with two types of carriers, if one of them exhibits blocking-contact characteristics.

Special quasirandom structures

1990-07-16

Alex Zunger , Su‐Huai Wei , L. G. Ferreira +1 more

Structural models used in calculations of properties of substitutionally random ${\mathit{A}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathit{B}}_{\mathit{x}}$ alloys are usually constructed by randomly occupying each of the N sites of a periodic cell by A or … Structural models used in calculations of properties of substitutionally random ${\mathit{A}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathit{B}}_{\mathit{x}}$ alloys are usually constructed by randomly occupying each of the N sites of a periodic cell by A or B. We show that it is possible to design ``special quasirandom structures'' (SQS's) that mimic for small N (even N=8) the first few, physically most relevant radial correlation functions of a perfectly random structure far better than the standard technique does. We demonstrate the usefulness of these SQS's by calculating optical and thermodynamic properties of a number of semiconductor alloys in the local-density formalism.

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Tunneling through a controllable vacuum gap

1982-01-15

G. Binnig , H. Rohrer , Ch. Gerber +1 more

We report on the first successful tunneling experiment with an externally and reproducibly adjustable vacuum gap. The observation of vacuum tunneling is established by the exponential dependence of the tunneling … We report on the first successful tunneling experiment with an externally and reproducibly adjustable vacuum gap. The observation of vacuum tunneling is established by the exponential dependence of the tunneling resistance on the width of the gap. The experimental setup allows for simultaneous investigation and treatment of the tunnel electrode surfaces.

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Percolation and Conduction

1973-10-01

Scott Kirkpatrick

Extensions of percolation theory to treat transport are described. Resistor networks, from which resistors are removed at random, provide the natural generalization of the lattice models for which percolation thresholds … Extensions of percolation theory to treat transport are described. Resistor networks, from which resistors are removed at random, provide the natural generalization of the lattice models for which percolation thresholds and percolation probabilities have previously been considered. The normalized conductance, $G$, of such networks proves to be a sharply defined quantity with a characteristic concentration dependence near threshold which appears sensitive only to dimensionality. Numerical results are presented for several families of $3D$ and $2D$ network models. Except close to threshold, the models based on bond percolation are accurately described by a simple effective medium theory, which can also treat continuous media or situations less drastic than the percolation models, for example, materials in which local conductivity has a continuous distribution of values. The present calculations provide the first quantitative test of this theory. A "Green's function" derivation of the effective medium theory, which makes contact with similar treatments of disordered alloys, is presented. Finally, a general expression for the conductance of a percolation model is obtained which relates $G$ to the spin-stiffness coefficient, $D$, of an appropriately defined model dilute ferromagnet. We use this relationship to argue that the "percolation channels" through which the current flows above threshold must be regarded as three dimensional.

Ferromagnetism in a Narrow, Almost Half-Filled<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>s</mml:mi></mml:math>Band

1966-07-08

Yosuke Nagaoka

We consider conduction electrons in a narrow $s$ band with a strong repulsive potential which acts when two electrons are at the same atomic site. It is assumed that the … We consider conduction electrons in a narrow $s$ band with a strong repulsive potential which acts when two electrons are at the same atomic site. It is assumed that the electron-transfer matrix elements are nonvanishing only between nearest-neighbor sites, and that the band is almost half-filled, or $|N\ensuremath{-}{N}_{e}|\ensuremath{\ll}N$, $N$ and ${N}_{e}$ being, respectively, the number of atoms and electrons in the crystal. Then it is proved quite rigorously that, if the repulsive potential is sufficiently strong, the ferromagnetic state with the maximum total spin is the ground state for simple cubic and body centered cubic structures as well as for face centered cubic and hexagonal closed packed structures with ${N}_{e}>N$, and is not the ground state for face centered cubic and hexagonal closed packed structures with ${N}_{c}<N$. For the former case, it is also shown that it is not the ground state if the repulsive potential is weaker than some critical value which is of the order $(\mathrm{bandwidth})\ifmmode\times\else\texttimes\fi{}\frac{N}{|N\ensuremath{-}{N}_{e}|}$.

A theory of the electrical breakdown of solid dielectrics

1934-07-02

Clarence Zener

In the modern theory of metallic conduction initiated by Bloch, conductors, semi-conductors, and non-conducting crystals may be represented by the same model. In this model each electron is supposed to … In the modern theory of metallic conduction initiated by Bloch, conductors, semi-conductors, and non-conducting crystals may be represented by the same model. In this model each electron is supposed to move freely in the periodic field of the lattice. Owing to this field, not all electronic energy levels are allowed; the allowed levels are grouped into bands, separated by energy intervals which are disallowed. If all the energy levels of a given band are occupied by electrons, then, according to the theory, these electrons can make no contribution to an electric current in the crystal. If all the bands are full, the crystal must be an insulator. Thus in an insulator there exist a number of energy bands which are completely full, and a number of bands of higher energy which, for a perfect crystal at the absolute zero of temperature, are empty. In a real non-conducting crystal, however, there will be a few electrons in the first unfilled band, owing to thermal excitation, impurities, etc. Their number is, however, too small to give an appreciable current at ordinary field strengths. As the field strength is increased, the current due to these few electrons increases steadily, but it will not show the sudden rise observed in dielectric breakdown. For this sudden rise it is necessary that the number of electrons in an unfilled band should suddenly increase as the field strength passes a critical value. Two distinct mechanisms have been suggested for this sudden increase. Of these, the first is a process analogous to the electrical breakdown of gases. In the absence of an external field, the few electrons in the upper band are in the lowest energy state of this band; under the action of an electric field, they are raised to higher levels. When one of these electrons reaches a sufficiently high level, it will give up energy to an electron in a lower (full) band, both electrons making a transition to a low level of the upper band. The process will then be repeated; the number of electrons in the upper band will thus increase exponentially with time as long as the electric field is maintained.

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The conductivity of thin metallic films according to the electron theory of metals

1938-01-01

K. Fuchs

The conductivity of thin films of the alkali metals has recently been measured in the H. W. Wills Physical Laboratory, Bristol*. It was found that as the thickness of the … The conductivity of thin films of the alkali metals has recently been measured in the H. W. Wills Physical Laboratory, Bristol*. It was found that as the thickness of the film is decreased to that of a few atomic layers the conductivity drops below that of the bulk metal. In the papers quoted the hypothesis was put forward that this effect is due to the shortening of the mean free paths of the conduction electrons of the metal by collisions with the boundaries of the film. The experimental results were compared with a formula derived on the basis of this hypothesis. This formula was, however, obtained subject to a number of simplifying assumptions, and it is the first purpose of this paper to obtain a more accurate formula. I also compare this formula with experiment, and make certain deductions about the surfaces of thin films.

Scanning tunneling microscopy observations on the reconstructed Au(111) surface: Atomic structure, long-range superstructure, rotational domains, and surface defects

1990-11-15

Johannes V. Barth , Harald Brune , G. Ertl +1 more

High-resolution scanning tunneling microscopy data on the reconstructed Au(111) surface are presented that give a comprehensive picture of the atomic structure, the long-range ordering, and the interaction between reconstruction and … High-resolution scanning tunneling microscopy data on the reconstructed Au(111) surface are presented that give a comprehensive picture of the atomic structure, the long-range ordering, and the interaction between reconstruction and surface defects in the reconstructed surface. On the basis of the atomically resolved structure, the stacking-fault-domain model involving periodic transitions from fcc to hcp stacking of top-layer atoms is confirmed. The practically uniform contraction in the surface layer along [11\ifmmode\bar\else\textasciimacron\fi{}0] indicates that the previously proposed soliton functionalisms are not correct descriptions for the fcc\ensuremath{\rightarrow}hcp stacking transition. The lateral displacement of \ensuremath{\sim}0.9 \AA{} in the ${(}_{\mathrm{\ensuremath{-}}1}^{22}$ $_{2}^{0}$) unit cell along [112\ifmmode\bar\else\textasciimacron\fi{}] is in good agreement with the transition between fcc and hcp stacking. The vertical displacement in the transition regions (0.20\ifmmode\pm\else\textpm\fi{}0.05 \AA{}) is largely independent of the tunneling parameters, while the atomic corrugation (0.2 \AA{} typically, up to 1 \AA{}) depends strongly on tunneling parameters and tip conditions.The two different stacking regions within the unit cell are directly identified from the domain pattern at step edges; fcc stacking is deduced for the wider areas and thus is energetically more favorable. A new long-range superstructure is reported. It is created by a correlated periodic bending of the parallel corrugation lines by \ifmmode\pm\else\textpm\fi{}120\ifmmode^\circ\else\textdegree\fi{} every 250 \AA{}, i.e., rotational domains are arranged in a zigzag pattern. Interactions on this scale indicate long-range elastic lattice strain. This structure reflects the overall tendency to isotropic contraction, combining the locally favorable uniaxial contraction and an effective isotropic contraction on a larger scale. Boundaries of rotational domains can also be formed by a termination of the reconstruction lines. Individual corrugation lines, separating different stacking regions, cannot disappear. The termination occurs in well-ordered, U-shaped connections of neighbored lines or by a complicated pattern of entangled corrugation lines. Steps and bulk defects do not inhibit the reconstruction, but can affect the local reconstruction pattern. In most cases steps are crossed by the reconstruction lines, and the strict correlation of the reconstruction pattern on the terraces, both in phase and orientation, reflects interaction over the step edge. Sometimes the reconstruction pattern at the steps resembles those found at rotational domain boundaries.

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Electron correlation in semiconductors and insulators: Band gaps and quasiparticle energies

1986-10-15

Mark S. Hybertsen , Steven G. Louie

We present a first-principles theory of the quasiparticle energies in semiconductors and insulators described in terms of the electron self-energy operator. The full dielectric matrix is used to evaluate the … We present a first-principles theory of the quasiparticle energies in semiconductors and insulators described in terms of the electron self-energy operator. The full dielectric matrix is used to evaluate the self-energy operator in the GW approximation: the first term in an expansion of the self-energy operator in terms of the dynamically screened Coulomb interaction (W) and the dressed Green's function (G). Quasiparticle energies are calculated for the homopolar materials diamond, Si, and Ge as well as for the ionic compound LiCl. The results are in excellent agreement with available experimental data. In particular, the indirect band gap is calculated as 5.5, 1.29, and 0.75 eV as compared with experimental gaps of 5.48, 1.17, and 0.744 eV for diamond, Si, and Ge, respectively. The Ge results include relativistic effects. The calculated direct gap for LiCl is within 5% of experiment. Viewed as a correction to the density-functional eigenvalues calculated with the local-density approximation, the present results show a correction dominated by a large jump at the gap. It is found that because of the charge inhomogeneity, the full dielectric screening matrix must be included, i.e., local-field effects are essential. The dynamical effects are also found to be crucial. The required dielectric matrices are obtained within the density-functional approach for the static case and extended to finite frequency with use of a generalized plasmon-pole model based on sum rules. The model reproduces the \ensuremath{\omega} and ${\ensuremath{\omega}}^{\mathrm{\ensuremath{-}}1}$ moments of the exact many-body response function. The qualitative features of the electron self-energy operator are discussed. Using the static Coulomb-hole--screened-exchange approximation for illustration, the role of local fields in the self-energy operator are explained. The role of dynamical renormalization is illustrated. The same qualitative features are observed in both the homopolar and ionic materials.

Anisotropy of the Electronic Work Function of Metals

1941-11-01

R. Smoluchowski

Work function is experimentally known to be different for different faces of a crystal by amounts ranging from one-tenth to half a volt. For tungsten the faces can be arranged … Work function is experimentally known to be different for different faces of a crystal by amounts ranging from one-tenth to half a volt. For tungsten the faces can be arranged according to decreasing work function as follows: 110, 211, 100 and finally 111. The explanations so far suggested for the differences of the work function are discussed and shown to give either an incorrect sequence or a wrong order of magnitude of the observed differences. The author uses the picture of Wigner and Bardeen according to which the work function is a sum of a volume contribution and a contribution due to a double layer on the surface of the metal. The origin of the latter can be described in the following manner. With every atom one can associate a polyhedron ("$s$-polyhedron") with the atom at its center, such that it contains all points nearer to the atom under consideration than to any other atom. If the distribution of the electron density within these polyhedra of the surface atoms was the same as for the inside atoms then there would be no double layer on the surface. However, this is not the case since the total energy is lowered by a redistribution of the electron cloud on the surface. There are two effects: the first is a partial spread of the charge out of the $s$-polyhedra and the second is a tendency to smooth out the surface of the polyhedra. In consequence of the second effect the surfaces of equal charge density are more nearly plane than in the original picture. The two effects have opposite influences and since they are comparable in magnitude, it is not possible to predict the sign of the total double layer without numerical computations. Some general formulae for the double layers are derived and discussed more fully in the case of a simple cubic and a body-centered cubic lattice. The minimum problem of the surface energy is solved for four faces of a body-centered crystal and the results are applied to the case of tungsten. One obtains the differences between the work functions for different directions. The results agree satisfactorily with the experimental data: assuming a reasonable density of the free electrons, one obtains the correct sequence of faces and the correct differences of the work function. The surface energies are calculated an d found in agreement with the observed stability of certain crystal faces.

Advances in Electronics and Electron Physics

1960-03-01

L. Marton , Robert L. Sproull

Digital techniques in electron off-axis holography, G. Ade optical symbolic substitution architectures, M.S. Alam and M.A. Karim semiconductor quantum devices, M. Cahay and S. Bandyopadhyay fuzzy relations and applications, B. … Digital techniques in electron off-axis holography, G. Ade optical symbolic substitution architectures, M.S. Alam and M.A. Karim semiconductor quantum devices, M. Cahay and S. Bandyopadhyay fuzzy relations and applications, B. de Baets and E. Kerre basis algorithms in mathematical morphology, R. Jones and I.D. Svalbe mirror-bank energy analyzers, S.P. Karetskaya et al.

Surface States and Rectification at a Metal Semi-Conductor Contact

1947-05-15

John Bardeen

Localized states (Tamm levels), having energies distributed in the "forbidden" range between the filled band and the conduction band, may exist at the surface of a semi-conductor. A condition of … Localized states (Tamm levels), having energies distributed in the "forbidden" range between the filled band and the conduction band, may exist at the surface of a semi-conductor. A condition of no net charge on the surface atoms may correspond to a partial filling of these states. If the density of surface levels is sufficiently high, there will be an appreciable double layer at the free surface of a semi-conductor formed from a net charge from electrons in surface states and a space charge of opposite sign, similar to that at a rectifying junction, extending into the semi-conductor. This double layer tends to make the work function independent of the height of the Fermi level in the interior (which in turn depends on impurity content). If contact is made with a metal, the difference in work function between metal and semi-conductor is compensated by surface states charge, rather than by a space charge as is ordinarily assumed, so that the space charge layer is independent of the metal. Rectification characteristics are then independent of the metal. These ideas are used to explain results of Meyerhof and others on the relation between contact potential differences and rectification.

Thin Film Phenomena

1970-01-01

K. L. Chopra , Julius Klerrer

Fundamental studies of microscopic wetting on organic surfaces. 1. Formation and structural characterization of a self-consistent series of polyfunctional organic monolayers

1990-01-01

Ralph G. Nuzzo , Lawrence H. Dubois , David L. Allara

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFundamental studies of microscopic wetting on organic surfaces. 1. Formation and structural characterization of a self-consistent series of polyfunctional organic monolayersRalph G. Nuzzo, Lawrence H. Dubois, and … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFundamental studies of microscopic wetting on organic surfaces. 1. Formation and structural characterization of a self-consistent series of polyfunctional organic monolayersRalph G. Nuzzo, Lawrence H. Dubois, and David L. AllaraCite this: J. Am. Chem. Soc. 1990, 112, 2, 558–569Publication Date (Print):January 1, 1990Publication History Published online1 May 2002Published inissue 1 January 1990https://pubs.acs.org/doi/10.1021/ja00158a012https://doi.org/10.1021/ja00158a012research-articleACS PublicationsRequest reuse permissionsArticle Views4166Altmetric-Citations1457LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Physics of Thin Films

1964-01-01

G. Hass , D. Gerstenberg

Properties of Semiconductor Surface Inversion Layers in the Electric Quantum Limit

1967-11-15

Frank Stern , W. E. Howard

The strong surface electric field associated with a semiconductor inversion layer quantizes the motion normal to the surface. The bulk energy bands split into electric sub-bands near the surface, each … The strong surface electric field associated with a semiconductor inversion layer quantizes the motion normal to the surface. The bulk energy bands split into electric sub-bands near the surface, each of which is a two-dimensional continuum associated with one of the quantized levels. We treat the electric quantum limit, in which only the lowest electric sub-band is occupied. Within the effective-mass approximation, we have generalized the energy-level calculation to include arbitrary orientations of (1) the constant-energy ellipsoids in the bulk, (2) the surface or interface, and (3) an external magnetic field. The potential associated with a charged center located an arbitrary distance from the surface is calculated, taking into account screening by carriers in the inversion layer. The bound states in the inversion layer due to attractive Coulomb centers are calculated for a model potential which assumes the inversion layer to have zero thickness. The Born approximation is compared with a phase-shift calculation of the scattering cross section, and is found to be reasonably good for the range of carrier concentrations encountered in InAs surfaces. The low-temperature mobility associated with screened Coulomb scattering by known charges at the surface and in the semiconductor depletion layer is calculated for InAs and for Si (100) surfaces in the Born approximation, using a potential that takes the inversion-layer charge distribution into account. The InAs results are in good agreement with experiment. In Si, but not in InAs, freeze-out of carriers into inversion-layer bound states is expected at low temperatures and low inversion-layer charge densities, and the predicted behavior is in qualitative agreement with experiment. An Appendix gives the phase-shift method for two-dimensional scattering and the exact cross section for scattering by an unscreened Coulomb potential.

�ber die Quantenmechanik der Elektronen in Kristallgittern

1929-07-01

Félix Bloch

The Electrical Resistance of Binary Metallic Mixtures

1952-07-01

Rolf Landauer

The existing theories of the resistivity of mixtures assume regular arrangements of the two components, rather than random mixtures. A theory for a random mixture is given, based on the … The existing theories of the resistivity of mixtures assume regular arrangements of the two components, rather than random mixtures. A theory for a random mixture is given, based on the assumption that each crystal acts as if surrounded by a homogeneous medium whose properties are those of the mixture. Comparisons with experiment are made. The experimental data that have been examined fall roughly into two classes. One class consists of mixtures, where the variation of resistivity with composition disagrees violently with this theory, making it clear that the assumptions made are completely inapplicable. The remaining class consists of mixtures which generally agree well with the theory.

Introduction to Mesoscopic Physics

1998-01-01

Y. Imry , M. Tinkham

Preface Preface to the second edition List of symbols 1. Introduction and a brief review of experimental systems 2. Quantum transport, Anderson Localization 3. Dephasing by coupling with the environment, … Preface Preface to the second edition List of symbols 1. Introduction and a brief review of experimental systems 2. Quantum transport, Anderson Localization 3. Dephasing by coupling with the environment, application to Coulomb electron-electron interactions in metals 4. Mesoscopic effects in equilibrium and static properties 5. Quantum interference effects in transport properties, the Landauer formulation and applications 6. The Quantum Hall Effect 7. Mesoscopics with superconductivity 8. Noise in mesoscopic systems 9. Concluding remarks A. The Kubo, linear response, formulation B. The Kubo-Greenwood Conductivity and the Edwards-Thouless Relationships C. The Aharonov-Bohm Effect and the Byers-Yang and Bloch Theorem D. Derivation of matrix elements in the diffusion regime E. Careful treatment of dephasing in 2D conductors at low temperatures F. Anomalies in the density of states (DOS) G. Quasiclassical theory of spectral correlations H. Details of the four-terminal formulation I. Universality of the conductance fluctuations in terms of the universal correlation of transmission eigenvalues J. The conductance of ballistic 'point contacts'

Elastic Properties of ZnS Structure Semiconductors

1970-05-15

Richard M. Martin

A simple phenomenological theory of the elastic constants of sphalerite structure crystals is presented and shown to apply within reasonable errors to the known experimental constants. The theory utilizes a … A simple phenomenological theory of the elastic constants of sphalerite structure crystals is presented and shown to apply within reasonable errors to the known experimental constants. The theory utilizes a form for bond-stretching ($\ensuremath{\alpha}$) and bending ($\ensuremath{\beta}$) forces first used by Keating, to which are added effective point-ion Coulombic forces. Also it is pointed out that regularities in the experimental elastic constants of these crystals are readily explained in terms of the ionicity ${f}_{i}$ defined by Phillips and Van Vechten. Of particular note are the shear constants which decrease markedly with ionicity. It is found that this decrease is described quantitatively by $\frac{\ensuremath{\beta}}{\ensuremath{\alpha}}\ensuremath{\propto}(1\ensuremath{-}{f}_{i})$, which confirms the interpretation of $\ensuremath{\beta}$, since bond-bending forces should vanish in the ionic limit ${f}_{i}\ensuremath{\rightarrow}1$. Other equally simple formulas for the forces in terms of only the bond length and ${f}_{i}$ are shown to predict all the constants with a rms accuracy of 10%.

Coherent-Potential Model of Substitutional Disordered Alloys

1967-04-15

Paul Soven

We introduce a model of a substitutional alloy based on the concept of an effective or coherent potential which, when placed on every site of the alloy lattice, will simulate … We introduce a model of a substitutional alloy based on the concept of an effective or coherent potential which, when placed on every site of the alloy lattice, will simulate the electronic properties of the actual alloy. The coherent potential is necessarily a complex, energy-dependent quantity. We evaluate the model for the simple case of a one-dimensional alloy of $\ensuremath{\delta}$-function potentials. In order to provide a basis for comparison, as well as to see if a simpler scheme will suffice, we also calculate the spectrum of the same alloy using the average $t$-matrix approximation introduced by Beeby. On the basis of these results, we conclude that the average $t$-matrix approximation is not adequate for the description of an actual transition-metal alloy, while the coherent-potential picture will provide a more reasonable facsimile of the density of states in such an alloy.

Extremely Low Frequency Plasmons in Metallic Mesostructures

1996-06-17

J. B. Pendry , A.J. Holden , Will Stewart +1 more

The plasmon is a well established collective excitation of metals in the visible and near UV, but at much lower frequencies dissipation destroys all trace of the plasmon and typical … The plasmon is a well established collective excitation of metals in the visible and near UV, but at much lower frequencies dissipation destroys all trace of the plasmon and typical Drude behavior sets in. We propose a mechanism for depression of the plasma frequency into the far infrared or even GHz band: Periodic structures built of very thin wires dilute the average concentration of electrons and considerably enhance the effective electron mass through self-inductance. Computations replicate the key features and confirm our analytic theory. The new structure has novel properties not observed before in the GHz band, including some possible impact on superconducting properties.

Optical Properties of Thin Solid Films

1956-03-01

O.S. Heavens , Stefan Singer

Highly convergent schemes for the calculation of bulk and surface Green functions

1985-04-01

M. P. López-Sancho , Javier Sancho , J. Rubio

The surface and bulk densities of states of a solid described by the stacking of principal layers are obtained by means of an iterative procedure which allows (i) the inclusion … The surface and bulk densities of states of a solid described by the stacking of principal layers are obtained by means of an iterative procedure which allows (i) the inclusion of 2n layers after n iterations, (ii) the simultaneous calculation of the Green functions for both the 'right' and 'left' surfaces as well as for the bulk (or central) principal layer, and (iii) the use of imaginary parts eta as small as one wishes in the energy without any large increase in computing time, so that the limit eta to 0 can really be obtained. As a by-product the authors obtain (i) the 'right' and 'left' transfer matrices of the 'effective field' or continuous fraction approach and (ii) a factorisation theorem which relates the Green functions of both surfaces to the Green functions of both surfaces to the Green functions of the bulk and the free metal atom.

Polarizability of a Two-Dimensional Electron Gas

1967-04-03

Frank Stern

The response of a two-dimensional electron gas to a longitudinal electric field of arbitrary wave vector and frequency is calculated in the self-consistent-field approximation. The results are used to find … The response of a two-dimensional electron gas to a longitudinal electric field of arbitrary wave vector and frequency is calculated in the self-consistent-field approximation. The results are used to find the asymptotic screened Coulomb potential and the plasmon dispersion for a plane of electrons imbedded in a three-dimensional dielectric.

Optical Properties of Ag and Cu

1962-11-15

Hannelore Ehrenreich , H. R. Philipp

Experimental data for the optical constants of Ag and Cu extending to 25 eV are discussed in terms of three fundamental physical processes: (1) free-electron effects, (2) interband transitions, and … Experimental data for the optical constants of Ag and Cu extending to 25 eV are discussed in terms of three fundamental physical processes: (1) free-electron effects, (2) interband transitions, and (3) collective oscillations. Dispersion theory is used to obtain an accurate estimate of the average optical mass characterizing the free-electron behavior over the entire energy range below the onset of interband transitions. The values are ${m}_{a}=1.03\ifmmode\pm\else\textpm\fi{}0.06$ for Ag and 1.42\ifmmode\pm\else\textpm\fi{}0.05 for Cu. The interband transitions to 11 eV are identified tentatively using Segall's band calculations. Plasma resonances involving both the conduction band and $d$ electrons are identified and described physically.

Theory and Application for the Scanning Tunneling Microscope

1983-06-20

J. Tersoff , D. R. Hamann

A theory is presented for vacuum tunneling between a real solid surface and a model probe with a locally spherical tip, applicable to the recently developed "scanning tunneling microscope." Calculations … A theory is presented for vacuum tunneling between a real solid surface and a model probe with a locally spherical tip, applicable to the recently developed "scanning tunneling microscope." Calculations for 2\ifmmode\times\else\texttimes\fi{}1 and 3\ifmmode\times\else\texttimes\fi{}1 reconstructions of Au(110) are in excellent agreement with recent experimental results, if an effective radius of curvature of 9 \AA{} is assumed for the tip.

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Optical Constants of the Noble Metals

1972-12-15

P. B. Johnson , R. W. Christy

The optical constants $n$ and $k$ were obtained for the noble metals (copper, silver, and gold) from reflection and transmission measurements on vacuum-evaporated thin films at room temperature, in the … The optical constants $n$ and $k$ were obtained for the noble metals (copper, silver, and gold) from reflection and transmission measurements on vacuum-evaporated thin films at room temperature, in the spectral range 0.5-6.5 eV. The film-thickness range was 185-500 \AA{}. Three optical measurements were inverted to obtain the film thickness $d$ as well as $n$ and $k$. The estimated error in $d$ was \ifmmode\pm\else\textpm\fi{} 2 \AA{}, and that in $n$, $k$ was less than 0.02 over most of the spectral range. The results in the film-thickness range 250-500 \AA{} were independent of thickness, and were unchanged after vacuum annealing or aging in air. The free-electron optical effective masses and relaxation times derived from the results in the near infrared agree satisfactorily with previous values. The interband contribution to the imaginary part of the dielectric constant was obtained by subtracting the free-electron contribution. Some recent theoretical calculations are compared with the results for copper and gold. In addition, some other recent experiments are critically compared with our results.

Periodic boundary conditions inab initiocalculations

1995-02-15

Guy Makov , M. C. Payne

The convergence of the electrostatic energy in calculations using periodic boundary conditions is considered in the context of periodic solids and localized aperiodic systems in the gas and condensed phases. … The convergence of the electrostatic energy in calculations using periodic boundary conditions is considered in the context of periodic solids and localized aperiodic systems in the gas and condensed phases. Conditions for the absolute convergence of the total energy in periodic boundary conditions are obtained, and their implications for calculations of the properties of polarized solids under the zero-field assumption are discussed. For aperiodic systems the exact electrostatic energy functional in periodic boundary conditions is obtained. The convergence in such systems is considered in the limit of large supercells, where, in the gas phase, the computational effort is proportional to the volume. It is shown that for neutral localized aperiodic systems in either the gas or condensed phases, the energy can always be made to converge as O(${\mathit{L}}^{\mathrm{\ensuremath{-}}5}$) where L is the linear dimension of the supercell. For charged systems, convergence at this rate can be achieved after adding correction terms to the energy to account for spurious interactions induced by the periodic boundary conditions. These terms are derived exactly for the gas phase and heuristically for the condensed phase.

Surface Plasmons in Thin Films

1969-06-10

E. N. Economou

The dispersion relations for surface plasma oscillations in normal metals are investigated for single- and multiple-film systems taking retardation effects into account. The simple dielectric function $\ensuremath{\epsilon}(\ensuremath{\omega})=1\ensuremath{-}\frac{{{\ensuremath{\omega}}_{p}}^{2}}{{\ensuremath{\omega}}^{2}}$ is found to … The dispersion relations for surface plasma oscillations in normal metals are investigated for single- and multiple-film systems taking retardation effects into account. The simple dielectric function $\ensuremath{\epsilon}(\ensuremath{\omega})=1\ensuremath{-}\frac{{{\ensuremath{\omega}}_{p}}^{2}}{{\ensuremath{\omega}}^{2}}$ is found to be adequate for the high-frequency region in which oscillations remain undamped. Two types of possible modes of oscillation are found. One type corresponds to dispersion relations which behave linearly for not-so-high frequency, with a phase velocity always smaller than the velocity of light in the dielectric, but at least ten times larger than the Fermi velocity, while the other type consists of high-frequency modes ($\ensuremath{\omega}\ensuremath{\sim}{\ensuremath{\omega}}_{p}$). The role of these oscillations in the problem of transition radiation is reexamined. In the case of a thin metal film, a new interpretation is proposed for the peak observed in the transition radiation spectrum. Finally, the work is extended to superconducting metals where, in the frequency range $\ensuremath{\hbar}\ensuremath{\omega}<2\ensuremath{\Delta}$ ($2\ensuremath{\Delta}$ is the superconducting energy gap), we have justified the use of a dielectric function of the same functional form as given above but with ${{\ensuremath{\omega}}_{p}}^{2}$ replaced by an almost frequency-independent quantity ${{\ensuremath{\omega}}_{\mathrm{ps}}}^{2}$, where ${\ensuremath{\omega}}_{\mathrm{ps}}=\frac{c}{{\ensuremath{\lambda}}_{\mathrm{ps}}}$ and ${\ensuremath{\lambda}}_{\mathrm{ps}}$ is the actual penetration depth. In this frequency range, the oscillations are essentially undamped and play an important role in the electromagnetic properties of the multiple-film systems, and particularly when the systems exhibit the ac Josephson effect.

Superlattice and Negative Differential Conductivity in Semiconductors

1970-01-01

L. Esaki , Raphael Tsu

We consider a one-dimensional periodic potential, or “superlattice,” in monocrystalline semiconductors formed by a periodic variation of alloy composition or of impurity density introduced during epitaxial growth. If the period … We consider a one-dimensional periodic potential, or “superlattice,” in monocrystalline semiconductors formed by a periodic variation of alloy composition or of impurity density introduced during epitaxial growth. If the period of a superlattice, of the order of 100 Å, is shorter than the electron mean free path, a series of narrow allowed and forbidden bands is expected due to the subdivision of the Brillouin zone into a series of minizones. If the scattering time of electrons meets a threshold condition, the combined effect of the narrow energy band and the narrow wave-vector zone makes it possible for electrons to be excited with moderate electric fields to an energy and momentum beyond an inflection point in the E-k relation; this results in a negative differential conductance in the direction of the superlattice. The study of superlattices and observations of quantum mechanical effects on a new physical scale may provide a valuable area of investigation in the field of semiconductors.

The Monte Carlo method for the solution of charge transport in semiconductors with applications to covalent materials

1983-07-01

Carlo Jacoboni , L. Reggiani

This review presents in a comprehensive and tutorial form the basic principles of the Monte Carlo method, as applied to the solution of transport problems in semiconductors. Sufficient details of … This review presents in a comprehensive and tutorial form the basic principles of the Monte Carlo method, as applied to the solution of transport problems in semiconductors. Sufficient details of a typical Monte Carlo simulation have been given to allow the interested reader to create his own Monte Carlo program, and the method has been briefly compared with alternative theoretical techniques. Applications have been limited to the case of covalent semiconductors. Particular attention has been paid to the evaluation of the integrated scattering probabilities, for which final expressions are given in a form suitable for their direct use. A collection of results obtained with Monte Carlo simulations is presented, with the aim of showing the power of the method in obtaining physical insights into the processes under investigation. Special technical aspects of the method and updated microscopic models have been treated in some appendixes.

Structural stability and lattice defects in copper:Ab initio, tight-binding, and embedded-atom calculations

2001-05-21

Y. Mishin , Michael J. Mehl , D. A. Papaconstantopoulos +2 more

We evaluate the ability of the embedded-atom method (EAM) potentials and the tight-binding (TB) method to predict reliably energies and stability of nonequilibrium structures by taking Cu as a model … We evaluate the ability of the embedded-atom method (EAM) potentials and the tight-binding (TB) method to predict reliably energies and stability of nonequilibrium structures by taking Cu as a model material. Two EAM potentials are used here. One is constructed in this work by using more fitting parameters than usual and including ab initio energies in the fitting database. The other potential was constructed previously using a traditional scheme. Excellent agreement is observed between ab initio, TB, and EAM results for the energies and stability of several nonequilibrium structures of Cu, as well as for energies along deformation paths between different structures. We conclude that not only TB calculations but also EAM potentials can be suitable for simulations in which correct energies and stability of different atomic configurations are essential, at least for Cu. The bcc, simple cubic, and diamond structures of Cu were identified as elastically unstable, while some other structures (e.g., hcp and 9R) are metastable. As an application of this analysis, nonequilibrium structures of epitaxial Cu films on (001)-oriented fcc or bcc substrates are evaluated using a simple model and atomistic simulations with an EAM potential. In agreement with experimental data, the structure of the film can be either deformed fcc or deformed hcp. The bcc structure cannot be stabilized by epitaxial constraints.

Maximally localized Wannier functions for entangled energy bands

2001-12-19

Ivo Souza , Nicola Marzari , David Vanderbilt

We present a method for obtaining well-localized Wannier-like functions (WF's) for energy bands that are attached to or mixed with other bands. The present scheme removes the limitation of the … We present a method for obtaining well-localized Wannier-like functions (WF's) for energy bands that are attached to or mixed with other bands. The present scheme removes the limitation of the usual maximally localized WF's method [N. Marzari and D. Vanderbilt, Phys. Rev. B 56, 12 847 (1997)] that the bands of interest should form an isolated group, separated by gaps from higher and lower bands everywhere in the Brillouin zone. An energy window encompassing N bands of interest is specified by the user, and the algorithm then proceeds to disentangle these from the remaining bands inside the window by filtering out an optimally connected N-dimensional subspace. This is achieved by minimizing a functional that measures the subspace dispersion across the Brillouin zone. The maximally localized WF's for the optimal subspace are then obtained via the algorithm of Marzari and Vanderbilt. The method, which functions as a postprocessing step using the output of conventional electronic-structure codes, is applied to the s and d bands of copper, and to the valence and low-lying conduction bands of silicon. For the low-lying nearly-free-electron bands of copper we find WF's which are centered at the tetrahedral-interstitial sites, suggesting an alternative tight-binding parametrization.

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Electron correlations in narrow energy bands

1963-11-26

John P. Hubbard

It is pointed out that one of the main effects of correlation phenomena in d - and f -bands is to give rise to behaviour characteristic of the atomic or … It is pointed out that one of the main effects of correlation phenomena in d - and f -bands is to give rise to behaviour characteristic of the atomic or Heitler-London model. To investigate this situation a simple, approximate model for the interaction of electrons in narrow energy bands is introduced. The results of applying the Hartree-Fock approximation to this model are examined. Using a Green function technique an approximate solution of the correlation problem for this model is obtained. This solution has the property of reducing to the exact atomic solution in the appropriate limit and to the ordinary uncorrelated band picture in the opposite limit. The condition for ferromagnetism of this solution is discussed. To clarify the physical meaning of the solution a two-electron example is examined.

Measurement of Sheet Resistivities with the Four-Point Probe

1958-05-01

F. M. Smits

Correction factors are evaluated for the measurement of sheet resistirities on two-dimensional rectangular and circular samples with the four-point probe. Diffused surface layers can be treated as two-dimensional structures, but … Correction factors are evaluated for the measurement of sheet resistirities on two-dimensional rectangular and circular samples with the four-point probe. Diffused surface layers can be treated as two-dimensional structures, but the factors are also useful in obtaining body resistivities on thin samples.

Handbook of Optical Constants of Solids

1985-01-01

Proceedings of the 17th International Conference on the Physics of Semiconductors

1985-01-01

James D. Chadi , Walter A. Harrison

Introduction to Superconductivity

1976-04-01

B.J. Maddock

Professor Tinkham writes with clarity, emphasizing the physical ideas underlying the theoretical approaches to superconductivity which form the basis of this excellent book. By avoiding certain techniques, such as the … Professor Tinkham writes with clarity, emphasizing the physical ideas underlying the theoretical approaches to superconductivity which form the basis of this excellent book. By avoiding certain techniques, such as the use of Green functions, and by analysing many practical situations, he has ensured that the text is accessible to graduate experimentalists and theoreticians alike.

Electronic Properties of Doped Semiconductors

1984-01-01

B. I. Shklovskiǐ , Alex L. Efros

Localized trimers inducing metallic states in sub-monolayer thin Bi films on InSb(111)A

2025-06-24

Rohit Yadav , Sandra Benter , Rainer Timm | Physical Review Materials

Low-dimensional topological states have transformed our understanding of charge transportation through quantum materials. Many relevant observations have been connected to bismuth (Bi) containing materials or ultrathin Bi films. Here, we … Low-dimensional topological states have transformed our understanding of charge transportation through quantum materials. Many relevant observations have been connected to bismuth (Bi) containing materials or ultrathin Bi films. Here, we studied sub-monolayer amounts of Bi deposition on the In-terminated InSb(111)A surface using various complementary surface science techniques. Bi deposition at elevated sample temperature results in well-ordered <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mo>(</a:mo><a:mn>2</a:mn><a:mo>×</a:mo><a:mn>2</a:mn><a:mo>)</a:mo></a:mrow></a:math> and <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mrow><b:mo>(</b:mo><b:mn>2</b:mn><b:mi>√</b:mi><b:mn>3</b:mn><b:mo>×</b:mo><b:mn>2</b:mn><b:mi>√</b:mi><b:mn>3</b:mn><b:mo>)</b:mo></b:mrow><b:mtext>−</b:mtext><b:mi mathvariant="normal">R</b:mi><b:msup><b:mn>30</b:mn><b:mo>∘</b:mo></b:msup></b:mrow></b:math> surface reconstructions. Scanning tunneling microscopy/spectroscopy (STM/S) data show an enhanced density of states at the interface of the two reconstructions and local Bi trimers over the <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mrow><d:mo>(</d:mo><d:mn>2</d:mn><d:mo>×</d:mo><d:mn>2</d:mn><d:mo>)</d:mo></d:mrow></d:math> reconstructed surface. Bi-induced metallic surface states crossing the Fermi level are observed and attributed exclusively to the localized trimer states through STS and angle-resolved photoemission spectroscopy (ARPES) results. Furthermore, the ARPES spectra show band splitting at the Γ point and degenerate surface states at the M point, which is associated with Rashba splitting due to strong Bi-substrate interaction. Thus we interpret the Bi/InSb(111)A, exhibiting spin-split metallic surface states induced by localized Bi structures, as a promising candidate for exploring low-dimensional states and spin dynamics in future quantum materials. Published by the American Physical Society 2025

Layer-Resolved Spin and Charge Interplay in H-, Ag-, and Au-Adsorbed Si(111) Surfaces: Insights into Metallicity and Magnetism

2025-06-23

Nasim Hassani | Silicon

Bipolarons on dry and wet reduced rutile (110) surfaces: A constrained density functional theory study

2025-06-20

NULL AUTHOR_ID | Physical review. B./Physical review. B

Fluence-dependent transient reflectivity measurements of a transition metal close to sub-d-band to Fermi surface transition

2025-06-18

S. A. Romashevskiy | Optics Letters

The stability, electronic and topological properties of Bi-doped PbPdO2: A first-principles study

2025-06-17

Xinyi Zheng , Wen-Ti Guo , Xiumei Kang +4 more | Journal of Physics Condensed Matter

Abstract Spin-gapless semiconductors (SGSs), as a new class of quantum materials, bridge conventional semiconductors and semi-metallic ferromagnets. Herein, the stability and topological properties of PbPdO 2 with Bi substituting for … Abstract Spin-gapless semiconductors (SGSs), as a new class of quantum materials, bridge conventional semiconductors and semi-metallic ferromagnets. Herein, the stability and topological properties of PbPdO 2 with Bi substituting for Pb are systematically analyzed through first-principles calculations. The results show that Bi substitution for Pb is thermodynamically stable under Pb-poor conditions. Significantly, under the effect of SOC, the doped system demonstrates topological properties via topological order analysis, confirming its status as a topological material. Our results not only clarify the optimal growth conditions and topological nature of Pb 0.5 Bi 0.5 PdO 2 , but also reveal the inherent link between SGSs and non-trivial topological states, thereby offering a theoretical foundation for the design of innovative spintronic devices featuring efficient spin transport and topological protection.

Dynamic buckling of Si tetramers on the Si(111)-7 × 7 surface

2025-06-17

R. A. Zhachuk , J. Coutinho , D. V. Sheglov | The Journal of Chemical Physics

The atomic structure of Si tetramers that form on the Si(111)-7 × 7 surface during homoepitaxy is investigated by means of first-principles calculations with the currently available atomistic model as … The atomic structure of Si tetramers that form on the Si(111)-7 × 7 surface during homoepitaxy is investigated by means of first-principles calculations with the currently available atomistic model as a starting point. It is demonstrated that the rectangular shape of the Si tetramer is unstable against buckling. The comparison of the calculated results with the available scanning tunneling microscopy (STM) data provides a new understanding of the problem, indicating that the recorded STM images are influenced by dynamic buckling.

States decoupled from the surface in short Si atomic chains

2025-06-13

NULL AUTHOR_ID | Physical review. B./Physical review. B

The DOS Functions and Einstein’s Photoemission in Semiconductors Having Parabolic Energy Bands Under Different Physical Conditions

2025-06-08

| Series on the foundations of natural science and technology

Charge Transport at Atomic Scales in 1D-Semiconductors: A Quantum Statistical Model Allowing Rigorous Numerical Studies.

2025-06-06

Róisín Braddell , Jone Uria–Albizuri , J.-B. Bru +1 more | PubMed

There has been a recent surge of interest in understanding charge transport at atomic scales. The motivations are myriad, including understanding the conductance properties of peptides measured experimentally. In this … There has been a recent surge of interest in understanding charge transport at atomic scales. The motivations are myriad, including understanding the conductance properties of peptides measured experimentally. In this study, we propose a model of quantum statistical mechanics which aims to investigate the transport properties of 1D-semiconductor at nanoscales. The model is a two-band Hamiltonian in which electrons are assumed to be quasi-free. It allows us to investigate the behaviour of current and quantum fluctuations under the influence of numerous parameters, showing the response with respect to varying voltage, temperature and length. We compute the current observable at each site and demonstrate the local behaviour generating the current.

Strange electric resistivity and heat capacity of Fe(Mn,Si) compared to Fermi metals and non-metallic solids

2025-06-01

Andrew Das Arulsamy , Ragavendran Venkatesan , J. Mayandi | Solid State Communications

Conductivity with Hall effect

2025-06-01

Yury Grabovsky | IOP Publishing eBooks

Fermi energy sensitive universal conductance fluctuations in anisotropic materials

2025-05-29

NULL AUTHOR_ID | Physical review. B./Physical review. B

Polarizabilities of low-lying states of silver

2025-05-27

NULL AUTHOR_ID

Strong pairing and symmetric pseudogap metal in double Kondo lattice model: From nickelate superconductor to tetralayer optical lattice

2025-05-22

NULL AUTHOR_ID

Probing spatial variation in AFM-measured adhesion: Implication of distributed nanoscale charge heterogeneity

2025-05-21

Yulong Yang , Weifeng Yuan , William P. Johnson +3 more

Valley-controlled photoswitching of metal–insulator nanotextures

2025-05-21

Hannes Böckmann , Jan Horstmann , Felix Kurtz +5 more

Heuristic investigation for valid application of the Tinkham formula in the Drude metal thin film

2025-05-20

Young Sun Lee , Sang Youn Ahn , Sung Ju Hong +1 more

<title>Abstract</title> The Tinkham formula has been used to approximately study transmission characteristics of electromagnetic waves through thin conducting films. For valid application of the formula, features of thin films such … <title>Abstract</title> The Tinkham formula has been used to approximately study transmission characteristics of electromagnetic waves through thin conducting films. For valid application of the formula, features of thin films such as thickness and electrical conductivity are restricted. Herein, we investigate applicable conditions of the Tinkham formula for various metal films of which electrical and optical properties satisfy the Drude model. Especially, we compare analytic and numerical results for the transmission of terahertz wave through various metal films, providing appropriate application conditions for the Tinkham formula.

Real-Time Monitoring of Thermally Induced Twisting–Untwisting of Noncubic Domains in Au Microcrystallites using X-ray Diffraction Microscopy

2025-05-20

Chaitali Sow , Abhisakh Sarma , Andreas Schropp +5 more

Au bipyramids hosting body-centered orthorhombic and tetragonal lattices (bc(o,t)) exhibit extraordinary stability at ambient conditions and even under high-temperature/high-pressure conditions. The phases undergo conversion to a conventional face-centered cubic (fcc) … Au bipyramids hosting body-centered orthorhombic and tetragonal lattices (bc(o,t)) exhibit extraordinary stability at ambient conditions and even under high-temperature/high-pressure conditions. The phases undergo conversion to a conventional face-centered cubic (fcc) lattice only during annealing at 700 °C due to the unlocking of the geometrically induced stresses. The spatial distribution of the phases in the crystallite volume has revealed fcc capped bc(o,t) lattices with two halves of the bipyramid twisted by ∼6° along the length with approximately ± 5% strain. Understanding the spatial distribution and dynamics of these phases at high temperatures can provide detailed information on their thermal stability. Herein, using nanoprobe scanning X-ray diffraction microscopy (SXDM), in situ annealing of the bc(o,t) Au bipyramid (∼1.5 μm long and 300 nm wide) has been performed at different temperatures (up to 800 °C). The study reveals untwisting of the domains assisted by the supplied high temperature, while the existing lattices undergo variation in parameters with negligible changes in proportion. The study reveals and picturizes the dynamic change in diffracting volumes across a wide temperature range. Notably, despite annealing, ∼83% of the bc(o,t) content is still retained (with different lattice parameters), proposing the annealing route to produce unusual metastable lattices of gold.

Synthesis and growth mechanisms of (3,1)-graphene nanoribbons on Cu(111): insights from STM and DFT analysis

2025-05-19

Yi‐Ying Sung , Federico Grillo , Renald Schaub

Abstract We present a comprehensive study on the bottom-up synthesis of chiral (3,1)-graphene nanoribbons (GNRs) on Cu(111) using two analogous precursors, 10,10'-dibromo-9,9'-bianthryl (DBBA) and bianthracene (BA). Through a Temperature-Programmed Growth … Abstract We present a comprehensive study on the bottom-up synthesis of chiral (3,1)-graphene nanoribbons (GNRs) on Cu(111) using two analogous precursors, 10,10'-dibromo-9,9'-bianthryl (DBBA) and bianthracene (BA). Through a Temperature-Programmed Growth (TPG) strategy supported by Scanning Tunnelling Microscopy (STM), we investigate the role of precursor diffusion, polymerization, and cyclodehydrogenation in GNR formation. Our results show that DBBA predominantly forms bisanthene due to restricted surface diffusion and premature cyclodehydrogenation, rendering it unsuitable for extended ribbon growth. In contrast, BA exhibits significantly higher surface mobility, leading to the formation of polyanthracene chains, which subsequently transform into long (3,1)-GNRs upon controlled annealing. We identify cyclodehydrogenation at chain termini as a key factor limiting ribbon length. Our findings provide new insights into optimizing growth conditions for extended GNRs on Cu(111), paving the way for their integration into future electronic and spintronic applications.

Evidence of Ultrashort Orbital Transport in Heavy Metals Revealed by Terahertz Emission Spectroscopy

2025-05-15

Zhensheng Tao , Tongyang Guan , Jiahao Liu +4 more

<title>Abstract</title> The orbital angular momentum of electrons offers a promising, yet largely unexplored, degree of freedom for ultrafast, energy-efficient information processing. As the foundation of orbitronics, understanding how orbital currents … <title>Abstract</title> The orbital angular momentum of electrons offers a promising, yet largely unexplored, degree of freedom for ultrafast, energy-efficient information processing. As the foundation of orbitronics, understanding how orbital currents propagate and convert into charge currents is essential – but remains elusive due to the challenge in disentangling orbital and spin dynamics in ultrathin films. Although orbital currents have been predicted to propagate over long distances in materials, recent theoretical studies argue that lattice symmetry may constrain their mean free paths (MFPs) to the scale of a single atomic layer. In this work, we provide the first direct experimental evidence for ultrashort orbital MFPs in heavy metals (HMs) – W, Ta, Pt – revealed by femtosecond terahertz emission spectroscopy. This is enabled by sub-nanometer-precision control of thin-film thickness using wedge-shaped HM|Ni heterostructures. By employing a multi-component terahertz-emission model, we quantitatively extract the orbital MFPs, consistently finding them shorter than their spin counterparts. Furthermore, control experiments <italic>rule out</italic> interfacial orbital-to-charge conversion as the dominant mechanism, confirming that the process is governed by the bulk inverse orbital Hall effect. Our findings resolve a central controversy in orbitronics and provide key insights into orbital transport and conversion mechanisms.

Calculations of pathways of precise P incorporation into chlorinated Si(100) surface

2025-05-15

Т. В. Павлова

The precise incorporation of a phosphorus atom into a silicon surface is essential for the fabrication of nanoelectronic devices in which the active area is formed from single impurities. The … The precise incorporation of a phosphorus atom into a silicon surface is essential for the fabrication of nanoelectronic devices in which the active area is formed from single impurities. The most accurate approach employs scanning tunneling microscopy lithography, which may be done with atomic precision. However, the accuracy decreases when phosphorus is incorporated into the surface because P substitutes one of two neighboring Si atoms with equal probability. Here, the P–Si exchange mechanism was studied theoretically on a chlorinated Si(100) surface with an asymmetric configuration of Cl vacancies surrounding the P atom. Density functional theory was used to estimate the activation barriers and exchange rates between a P atom and neighboring Si atoms on a Si(100)-2 × 1-Cl surface with three Cl vacancies. The calculation of various P–Si exchange pathways revealed that phosphorus has a higher probability of substituting one Si atom than the others due to the asymmetric configuration of Cl vacancies. Based on the theoretical study of the P–Si exchange mechanism and experimental results from previous studies, a scheme for controlled P incorporation into the silicon surface without uncertainty is proposed.

Spectroscopic visualization of hard quasi-one-dimensional superconductivity induced in nanowires deposited on a quasi-two-dimensional indium film

2025-05-13

NULL AUTHOR_ID

Charge Transport Across Single Molecules at the Metal–Superconductor Interface

2025-05-10

Lorenz Meyer , Maximilian Kögler , Ankur Das +3 more

Abstract The understanding of electron transport through single atoms or molecules is important for the progress in realizing molecular electronics. Including a superconducting electrode in such junctions is particularly appealing … Abstract The understanding of electron transport through single atoms or molecules is important for the progress in realizing molecular electronics. Including a superconducting electrode in such junctions is particularly appealing because of the nondissipative character of the charge flow and the associated opportunity of conceiving low‐loss electronic circuits. Moreover, low‐energy excitations that are visible in the highly resolved spectroscopy of the current contain valuable information on electron pairing and pair breaking interactions. This Perspective discusses the appealing physics underlying the current flow across single atoms and molecules anchored to normal‐metal and superconducting electrodes, unveils open questions, and suggests prospective experiments.

Quantum confinement theory of ultra-thin films: electronic, thermal and superconducting properties

2025-05-09

Alessio Zaccone

Abstract The miniaturization of electronic devices has led to the prominence, in technological applications, of ultra-thin films with a thickness ranging from a few tens of nanometers to just about … Abstract The miniaturization of electronic devices has led to the prominence, in technological applications, of ultra-thin films with a thickness ranging from a few tens of nanometers to just about 1–2 nm. While these materials are still effectively 3D in many respects, traditional theories as well as ab initio methods struggle to describe their properties as measured in experiments. In particular, standard approaches to quantum confinement rely on hard-wall boundary conditions, which neglect the unavoidable, ubiquitous, atomic-scale irregularities of the interface. Recently, a unified theoretical approach to quantum confinement has been proposed which is able to effectively take the real nature of the interface into account, and can efficiently be implemented in synergy with microscopic theories. Its predictions for the electronic properties such as the electrical conductivity of semiconductor thin films or the critical temperature of superconducting thin films, have been successfully verified in comparison with experimental data. The same confinement principles lead to new laws for the phonon density of states and for the heat capacity of thin films, again in agreement with the available experimental data.

Low-energy electron microscopy investigation of germanene segregation on Ag(111) thin films

2025-05-08

Hiroki Hibino , Akio Ohta , Hiroyuki Kageshima +1 more

Abstract We used low-energy electron microscopy to investigate the formation processes of various surface structures on Ag(111) thin films grown on Ge(111) during Ge segregation. During annealing the Ag(111) samples … Abstract We used low-energy electron microscopy to investigate the formation processes of various surface structures on Ag(111) thin films grown on Ge(111) during Ge segregation. During annealing the Ag(111) samples cleaned by Ar + sputtering, the Ag 2 Ge surface alloy first appeared along the Ag grain boundaries, signifying preferential diffusion of Ge atoms through these boundaries. Subsequent annealing at higher temperatures induced the phase transformation from the surface alloy to germanene. However, further higher temperature annealing caused back-diffusion of Ge atoms into the Ag thin films, reverting to the surface alloy. Formation of the ordered (7√7×7√7)R±19.1° germanene required cooling from high temperatures around 500 °C. However, high-temperature annealing occasionally resulted in the formation of three-dimensional (3D) Ge islands on the surface. During cooling, the 3D islands absorbed Ge atoms from the surrounding germanene, triggering phase transformation to the surface alloy in the vicinity of the islands.

Modification of single-hole-like states by configuration mixing in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi/><mml:mrow><mml:mn>99</mml:mn><mml:mo>−</mml:mo><mml:mo>−</mml:mo><mml:mn>131</mml:mn></mml:mrow></mml:msup></mml:math> In

2025-05-08

NULL AUTHOR_ID

Cation-Induced Dipole Moments on Single-Crystal Metal Surfaces

2025-05-05

Fabiola Domínguez-Flores , Axel Groß , Wolfgang Schmickler

Theoretical studies of optically induced high spin polarization and cubic anisotropy in cubic semiconductors

2025-05-04

M. Idrish Miah

Theoretical studies of optical spin polarization and cubic anisotropy in cubic semiconductors GaAs and GaSb are performed. We use Kane wave functions to calculate the eight-level transition matrix elements permitted … Theoretical studies of optical spin polarization and cubic anisotropy in cubic semiconductors GaAs and GaSb are performed. We use Kane wave functions to calculate the eight-level transition matrix elements permitted by the optical selection rules. It is found that the spin polarization depends on semiconductor, the pumping direction as well as the photon energy. A high spin polarization of about 55% is obtained for GaSb. The anisotropic effect in these cubic crystals is clearly seen. The band edge polarization is found to be flatter and higher for GaAs than that for GaSb. The results are discussed in comparison with the experimental data available in the literature.

Two-dimensional superconductivity of epitaxial tantalum films

2025-05-01

X. P. Chen , Chenjia Tang , Linpeng Yao +4 more

Adsorption analysis of Fe-ZQ on Cu(110) and V-ZQ on Au(110) using density functional theory

2025-05-01

Hassan Denawi , R. Hayn

Maximizing the chirality of bound states in the continuum by Inverse Design

2025-04-30

Chen He , Ning Li , Yan Zhao +6 more

Doping-driven robust superconductivity in tungsten for single-photon detection

2025-04-28

Liang Ma , Wei Chen , Hao Wang +7 more

Elemental superconductors are widely applied in quantum electronic devices, providing a homogenous research platform for both fundamental science and revolutionary technologies. However, their application in superconducting electronics remains a challenge … Elemental superconductors are widely applied in quantum electronic devices, providing a homogenous research platform for both fundamental science and revolutionary technologies. However, their application in superconducting electronics remains a challenge due to the ultralow operation temperatures and suboptimal stability. Here, we develop a nitrogen-doping strategy to enhance the superconductivity of ultrathin amorphous superconductors for single-photon detection. The interstitial N dopants induce the amorphization of W, resulting in an enhanced superconducting transition temperature of 4.4 K from 0.01 K (α-W). Furthermore, the surface nitroxide passivation layer ensures smooth and homogeneous topography at the wafer scale and provides strong chemical stability for nanodevice fabrication in a 6.0-nm-thick nitrogen-doped amorphous tungsten (NAW) film. Consequently, we achieve NAW-based infrared SNSPDs with saturated quantum efficiency at an operation temperature of &gt;1 K. This doping strategy can be applied to more elemental superconductors and, thus, promote their practical use in electronic devices.

Topologically constrained obstructed atomic limits in quasi-one-dimensional systems

2025-04-28

Milan Damnjanović , I. Milošević

Abstract Possible forms of obstructed atomic limits in quasi-one-dimensional systems are studied within the framework of line group symmetry. This is accomplished by revisiting the standard theory with an emphasis … Abstract Possible forms of obstructed atomic limits in quasi-one-dimensional systems are studied within the framework of line group symmetry. This is accomplished by revisiting the standard theory with an emphasis on its group-theoretical background, synthesizing the insights into a theorem that eﬃciently identiﬁes potential cases. The framework is then applied across the classes of quasi-one-dimensional systems, where the obstructed atomic limit serves as the primary criterion for topological characterization. The results are systematically organized and displayed, supported by a series of illustrative examples for clarity and insight.&#xD;

Growth and characterization of Ag layers on Mo(110) using LEED, XPS and ARPES

2025-04-25

S. DAS , Arunava Kar , Subrata Paul +1 more

Ballistic transport in nanodevices based on single-crystalline Cu thin films

2025-04-24

Gil‐Ho Lee , Young Jin Cho , Su Jae Kim +7 more

<title>Abstract</title> In ballistic transport, the movement of charged carriers remains unimpeded by scattering events. In this limit, microscopic parameters such as crystal momentum, spin and quantum phases are well conserved, … <title>Abstract</title> In ballistic transport, the movement of charged carriers remains unimpeded by scattering events. In this limit, microscopic parameters such as crystal momentum, spin and quantum phases are well conserved, allowing electrons to maintain their quantum coherence over longer distances. Nanoscale materials, such as carbon nanotubes, graphene, and nanowires, exhibit ballistic transport. However, their scalability in devices is significantly limited. While deposited metal films offer excellent scalability for nanodevices, their short electronic mean free paths hinder ballistic transport. In this study, we investigated the electronic transport in cross-geometry devices fabricated with 90-nm-thick Cu films without grain boundaries. We demonstrated ballistic transport in devices with channel widths less than 150 nm at temperatures below 85 K by measuring via negative bend resistance measurements. Our findings establish a novel and scalable platform for exploring the intrinsic quantum mechanical properties of Cu, advancing both the fundamental understanding of quantum transport in metals and its practical applications in next-generation electronic quantum technologies.