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A. A. Yushkanov

Publications and source records attributed to A. A. Yushkanov.

At least 73 records · Page 4Linked to original sources
arXiv2011

Landou's Half-Space Problem of Degenerate Plasma Oscillations with Specular-Accommodative Boundary Conditions

In the present paper the linearized problem of half-space plasma oscillations in external longitudinal alternating electric field is solved analytically. Specular - accommodative boundary conditions of electron reflection from the plasma boundary are considered. Coefficients of continuous and discrete spectra of the problem are found, and electron distribution function on the plasma boundary and electric field are expressed in explicit form.

math-ph↗
arXiv2011

Interaction of the Electromagnetic p-Wave with Thin Metal Film in the Field of Resonant Frequencies

It is shown that for thin metallic films thickness of which does not exceed thickness of skin layer, the problem allows analytical solution. In the field of resonant frequencies the analysis of dependence of coefficients of transmission, reflection and absorbtion on an electromagnetic wave is carried out. Dependence on pitch angle, thickness of the layer and coefficient of specular reflection and on effective electron collision frequency is carried out. The formula for contactless determination (calculation) of a thickness of a film by observable resonant frequencies is deduced.

math-ph↗
arXiv2010

Constructing a Model Transport Equation for a Massless Bose Gas and its Analytic Solution

A model kinetic equation is constructed for the transport of a massless Bose gas. This equation is applied to solution of the boundary value problem for the transport of radiation in the half-space occupied by a dispersive medium that is in local thermal equilibrium with the radiation. It is shown that the difference in temperature between the dispersive medium and the incident radiation depends substantially on the character of the scattering properties of the particles of the medium.

math-ph↗
arXiv2010

Surface Plasmons in Thin Metallic Films for Case Antisymmetrical Configuration of Magnetic Field

For the first time it is shown that for thin metallic films thickness of which does not exceed thickness of skin - layer, the problem of description of surface plasma oscillations allows analytical solution under arbitrary ratio of length of electrons free path and thickness of a film. The dependance of frequency of surface plasma oscillations on wave number is carried out. We consider a case of specularity - diffusive boundary value problems.

math-ph↗
arXiv2010

Surface Plasmons in Thin Metallic Films

For the first time it is shown that for thin metallic films thickness of which not exceed thickness of skin -- layer, the problem of description of surface plasma oscillations allows analytical solution by arbitrary ratio between length of electrons free path and thickness of a film. The dependance of frequency surface plasma oscillations on wave number is carry out.

math-ph↗
arXiv2010

Interaction of the Electromagnetic p-Waves with Thin Metal Films

For the first time it is shown that for thin metallic films thickness of which not exceed thickness of skin-layer, the problem allows analytical solution for arbitrary boundary value problems. The analysis of dependence of coefficients of transmission, reflection and absorbtion on angle incidence, thickness of films and coefficient of specular reflection is carried out.

math-ph↗
arXiv2010

Interaction of the Electromagnetic S-Wave with the Thin Metal Film

It is shown that for thin metal films, thickness of which does not exceed a thickness of a skin-layer, the problem allows analytical solution for any boundary conditions. The analysis of transmission, reflection and absorption of an electromagnetic wave coefficients depending on a angle of incidence, thickness of a layer, coefficient of specular reflection and frequency of oscillations of electromagnetic field is carried out.

math-ph↗
arXiv2010

Friedel oscillations in quantum degenerate collisional plasma. Screening of point charge

Research of influence of collisions on Friedel oscillations in quantum degenerate collisional plasma (T=0) is carried out for the first time. It is shown that presence of collisions in plasma leads to exponential decreasing of amplitude and phase shift of the Friedel oscillations. In linear approximation the phase shift is equal to the half of quantity inverse to product of Fermi's wave number by free length path of electrons. The correct expression for longitudinal dielectric permeability of the quantum collisional plasma found by the authors (see arxiv:1001.3937 [math-ph] 22 Jan 2010) is used.

math-ph↗
arXiv2010

Transverse electric conductivity of quantum collisional plasmas

Formulas for calculation of transverse dielectric function and transverse electric conductivity in quantum collisional plasmas under arbitrary degree of degeneracy of the electron gas are received. The Wigner - Vlasov - Boltzmann kinetic equation with collision integral in BGK (Bhatnagar, Gross and Krook) form in coordinate space is used. Various special cases are investigated. The case of fully degenerate quantum plasma was considered separately. Comparison with Lindhard's formula has been realized.

math-ph↗
arXiv2010

Landau Diamagnetism of Degenerate Collisional Plasma

For the first time the kinetic description of Landau diamagnetism for degenerate collisional plasma is given. The correct expression for transverse electric conductivity of the quantum plasma, found by authors (see arXiv:1002.1017 [math-ph] 4 Feb 2010) is used. In work S. Dattagupta, A.M. Jayannavar and N. Kumar [Current science, V. 80, No. 7, 10 April, 2001] was discussed the important problem of dissipation (collisions) influence on Landau diamagnetism. The analysis of this problem is given with the use of exact expression for transverse conductivity of quantum plasma.

math-ph↗
arXiv2010

Transverse electric conductivity of quantum collisional maxwellian plasma

Formulas for calculation of transverse dielectric function and transverse electric conductivity in quantum collisional Maxwellian plasma are obtained. The Wigner -- Vlasov -- Boltzmann kinetic equation with collision integral in BGK (Bhatnagar, Gross and Krook) form in coordinate space is used. Various special cases are in\-ves\-ti\-gated. Comparison with Lindhard's formula has been carried out.

math-ph↗
arXiv2010

Longitudinal dielectric permettivity of quantum Maxwell collisional plasmas

The kinetic equation of Wigner -- Vlasov -- Boltzmann with collision integral in relaxation BGK (Bhatnagar, Gross and Krook) form in coordinate space for quantum non--degenerate (Maxwellian) collisional plasma is used. Exact expression (within the limits of considered model) is found. The analysis of longitudinal dielectric permeability is done. It is shown that in the limit when Planck's constant tends to zero of expression for dielectric permettivity transforms into the classical case of dielectric permettivity. At small values of wave number it has been received the solution of the dispersion equation. Damping of plasma oscillations has been analized. The analytical comparison with the dielectric Mermin' function received with the use of the kinetic equation in momentum space is done. Graphic comparison of the real and imaginary parts of dielectric permettivity of quantum and classical plasma is done also.

math-ph↗
arXiv2010

Longitudinal permeability of collisional plasmas under arbitrary degree of degeneration of electron gas

Electric conductivity and dielectric permeability of the non-degenerate electronic gas for the collisional plasmas under arbitrary degree of degeneration of electron gas is found. The kinetic equation of Wigner - Vlasov - Boltzmann with collision integral in relaxation form BGK (Bhatnagar, Gross and Krook) in coordinate space is used. Dielectric permeability with using of the relaxation equation in the momentum space has been received by Mermin. Comparison with Mermin's formula has been realized. It is shown, that in the limit when Planck's constant tends to zero expression for dielectric permeability passes in the classical.

math-ph↗
arXiv2010

Skin Effect Problem with Diffusion Boundary Conditions in Maxwell Plasma

The analytical method of solving the boundary problems for a system of equations describing the behaviour of electrons and an electric field in the Maxwell plasma half-space is developed. Here the diffusion reflection of electrons from the surface as a boundary condition is supposed. The exact solution for boundary value problem of the Vlasov-Maxwell equations through the eigenfunctions of the discrete spectrum and the continuous spectrum is obtained. The method of decomposition by eigenfunctions of discrete and continuous spectrum is used. The exact expression for the surface impedance also is obtained.

math-ph↗
arXiv2010

Plasma waves reflection from a boundary with specular accommodative boundary conditions

In the present work the linearized problem of plasma wave reflection from a boundary of a half--space is solved analytically. Specular accommodative conditions of plasma wave reflection from plasma boundary are taken into consideration. Wave reflectance is found as function of the given parameters of the problem, and its dependence on the normal electron momentum accommodation coefficient is shown by the authors. The case of resonance when the frequency of self-consistent electric field oscillations is close to the proper (Langmuir) plasma oscillations frequency, namely, the case of long wave limit is analyzed. Refs. 17. Figs. 6.

math-ph↗
arXiv2010

Temperature jump in degenerate quantum gases in the presence of a Bose - Einstein condensate

We construct a kinetic equation modeling the behavior of degenerate quantum Bose gases whose collision rate depends on the momentum of elementary excitations. We consider the case where the phonon component is the decisive factor in the elementary excitations. We analytically solve the half-space boundary value problem of the temperature jump at the boundary of the degenerate Bose gas in the presence of a Bose -- Einstein condensate.

math-ph↗