scholarly journals К модельному описанию электронного спектра графеноподобных Янус-структур

2022 ◽  
Vol 64 (2) ◽  
pp. 277
Author(s):  
С.Ю. Давыдов
Keyword(s):  
Electronic Spectra ◽  
Function Method ◽  
Hexagonal Lattice ◽  
Tight Binding ◽  
Mechanical Deformation ◽  
Two Dimensional ◽  
Binding Theory ◽  
Effective Masses ◽  
Magnetic States ◽  
Analytical Expressions

Model of C – AB – D Janus structure as the compound formed by the interacting through atoms А and В dimers А – С and В – D, where А and В atoms are in the sites of two-dimensional hexagonal lattice and C and D atoms are on the opposite sides from AB list is proposed. In the scope of tight-binding theory and Green’s function method general equation for the dispersion low is obtained. The particular cases of C – AА – D и А – AB – В compounds are considered and analytical expressions for their electronic spectra is fulfilled. The effect of the external mechanical deformation on the band parameters including effective masses is examined. Problem of the magnetic states in Janus compounds is discussed.

scholarly journals Низкоразмерные структуры карбида кремния: аналитические оценки характеристик электронного спектра

2020 ◽  
Vol 54 (5) ◽  
pp. 446
Author(s):  
С.Ю. Давыдов
Keyword(s):  
Silicon Carbide ◽  
Electronic Structure ◽  
Function Method ◽  
Tight Binding ◽  
Band Gaps ◽  
Tight Binding Approximation ◽  
One Dimensional ◽  
Dielectric Substrates ◽  
Effective Masses ◽  
Analytical Expressions

Abstract Using the Green’s function method within the tight-binding approximation, the electronic structure of an infinite silicon-carbide sheet, and nanoribbons and one-dimensional chains cut from it, is considered. Analytical expressions for band gaps, electron effective masses and characteristic velocities are derived. The effect of metal and dielectric substrates on the band characteristics is discussed.

scholarly journals Простые модели латеральных гетероструктур

2018 ◽  
Vol 60 (7) ◽  
pp. 1389
Author(s):  
С.Ю. Давыдов
Keyword(s):  
Charge Transfer ◽  
Density Of States ◽  
Function Method ◽  
Tight Binding ◽  
Tight Binding Approximation ◽  
Densities Of States ◽  
Infinite Lattices ◽  
Band Spectra ◽  
Analytical Expressions ◽  
Lateral Heterostructure

AbstractGeneral analytical expressions for densities of states of a lateral heterostructure, formed by the contact of two square semi-infinite lattices with single-band and two-band spectra, were obtained in the tight-binding approximation by the Green’s function method. The semi-elliptical density of states was used for numerical estimates, and the model of two interacting dimers was proposed to estimate the charge transfer. Application of this approach to description of lateral epitaxial and graphene-like heterostructures is discussed.

scholarly journals Электронный спектр капсулированных монослоев: аналитические результаты

2021 ◽  
Vol 47 (13) ◽  
pp. 52
Author(s):  
С.Ю. Давыдов
Keyword(s):  
Green’S Function ◽  
Effective Mass ◽  
Strong Coupling ◽  
Green's Function ◽  
Function Method ◽  
Energy Gap ◽  
Green’S Function Method ◽  
Effective Masses ◽  
Analytical Expressions

Green’s function method is used to find the dispersion low for a monolayer (ML) placed be-tween two crystalline slabs. Weak- and strong-coupling regimes are considered in details. For the systems graphene, hBN – metallic ML – SiC polytypes analytical expressions for the ML electron effective masses are obtained. It is shown that the effective mass decreases with the increase of the SiC polytype energy gap.

scholarly journals Динамика распада водородных кластеров на поверхности графена и стоун-уэльсовского графена

2020 ◽  
Vol 62 (12) ◽  
pp. 2181
Author(s):  
А.И. Подливаев
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Elastic Constants ◽  
Function Method ◽  
Tight Binding ◽  
Quantum Capacitance ◽  
Parabolic Approximation ◽  
Green’S Function Method ◽  
Effective Masses ◽  
Anderson Models

Green’s function method together with the tight-binding approach are used to get analytical estimations for the electron bands dispersions. The parabolic approximation is proposed which permits to find carriers effective masses and quantum capacitance. With the use of the Koster – Slater and Haldane – Anderson models the problem on the local states of defects is considered. Analytical estimates of the specific phonon frequencies and elastic constants are given. The obtained results are compared with the data available.

Electronic Structure of Vacancy-Phosphorus Impurity Complexes in Silicon

1989 ◽  
Vol 163 ◽  
Author(s):  
Hongqi Xu ◽  
U. Lindefelt
Keyword(s):  
Electronic Structure ◽  
Function Method ◽  
Energy Levels ◽  
Tight Binding ◽  
Nearest Neighbour ◽  
Binding Theory ◽  
Self Consistent ◽  
Phosphorus Impurity ◽  
Semi Empirical ◽  
Shed Light

AbstractWe present a systematic theoretical investigation on four vacancy-phosphorus impurity complexes in silicon, i.e., a vacancy with one through four phosphorus impurities on the nearest neighbour sites of the vacancy, using a semi-empirical self-consistent tight-binding theory. The calculations are based on the Lanczos-Haydock recursion Green’s function method. The predicted energy levels in the band gap for the five cases, the isolated Si vacancy and the four complexes, show a remarkable regularity. We shed light on this regularity by relating it to the localization of the wavefunctions on the Si and P atoms surrounding the vacancy. We compare our results with experimental work.

scholarly journals Модельные оценки свойств флюорографена

2021 ◽  
Vol 63 (1) ◽  
pp. 158
Author(s):  
С.Ю. Давыдов
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Elastic Constants ◽  
Function Method ◽  
Tight Binding ◽  
Quantum Capacitance ◽  
Parabolic Approximation ◽  
Green’S Function Method ◽  
Effective Masses ◽  
Anderson Models

Green’s function method together with the tight-binding approach are used to get analytical estimations for the electron bands dispersions. The parabolic approximation is proposed which permits to find carriers effective masses and quantum capacitance. With the use of the Koster – Slater and Haldane – Anderson models the problem on the local states of vacancies is considered. Analytical estimates of the specific phonon frequencies and elastic constants are given. The obtained results are compared with the data available.

CALCULATION OF THE DEPENDENCE OF THE DISTANCE TO THE LOCATED OBJECT FROM THE CORNER POSITION OF THE VEHICLE LINE

2018 ◽  
pp. 14-18
Author(s):  
V. V. Artyushenko ◽  
A. V. Nikulin
Keyword(s):  
Real Time ◽  
Statistical Physics ◽  
Angular Position ◽  
Three Dimensional ◽  
Line Of Sight ◽  
Two Dimensional ◽  
Radar Station ◽  
Flight Mode ◽  
Vector Algebra ◽  
Analytical Expressions

To simulate echoes from the earth’s surface in the low flight mode, it is necessary to reproduce reliably the delayed reflected sounding signal of the radar in real time. For this, it is necessary to be able to calculate accurately and quickly the dependence of the distance to the object being measured from the angular position of the line of sight of the radar station. Obviously, the simplest expressions for calculating the range can be obtained for a segment or a plane. In the text of the article, analytical expressions for the calculation of range for two-dimensional and three-dimensional cases are obtained. Methods of statistical physics, vector algebra, and the theory of the radar of extended objects were used. Since the calculation of the dependence of the range of the object to the target from the angular position of the line of sight is carried out on the analytical expressions found in the paper, the result obtained is accurate, and due to the relative simplicity of the expressions obtained, the calculation does not require much time.

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