S. I. Khankina

Surface electron states produced by a Rayleigh wave

The electronic properties of a semiconductor bounded by an uneven surface representing an infinitely high potential barrier are investigated. The surface irregularities are produced by a Rayleigh acoustic wave. It is shown that, on the boundary of a semiconductor, surface electron states (waves) may arise whose dispersion laws are obtained under the conditions when conduction electrons are located either in or outside the field of the acoustic wave. Existence domains of surface electron states are found that are distinguished by their physical properties. These domains are separated by a band gap whose width is determined by the height of irregularities.

Fast charge energy losses in structures with a 2D electron gas

Fast charge energy losses for the excitation of natural oscillations in media with a 2D plasma sheath are studied. A semiconducting (dielectric) cylinder-2D plasma sheath-vacuum system is considered. Dispersion relations describing natural oscillations in such a system are derived. Energy losses of a point charge rectilinearly and uniformly moving over and inside the cylinder are found. The loss of energy by a moving charged ring embracing the system (specifically, a nanotube) is considered.

Interaction of surface plasmons with fluxes of charged particles crossing the interface between two media

Surface plasmon instability appearing during the interaction of plasmons with a flux of charged particles crossing the interface between media with different electromagnetic properties is predicted. The conditions under which instability appears are determined and the increments are found. The influence of the potential barrier at the interface on the interaction of surface plasmons with charged particles is investigated.

Energy losses analysis of charged particle moving in inhomogeneous medium

Energy losses of a charged particle moving along a spiral path above the surface of a dielectric or metal cylinder were determined using Maxwells equations. The conditions of gyrosynchrotron radiation of electromagnetic waves in the system were formulated. Obtained results are important for understanding of generation mechanisms of electromagnetic waves in electrodynamic systems that are the basis of microwave oscillators.

The energy loss of high-velocity charges in the structures with two-dimensional electron gas

The energy loss of high-velocity charges at the excitation of eigen modes in mediums containing two-dimensional plasma layer were studied. The following structures were studied: semiconductor (or dielectric) cylinder-plasma layer-vacuum. The corresponding dispersion equations describing eigen modes of these systems were obtained. The energy loss of the point charge moving linear and uniformly above cylinder or inside it were found. The features of energy loss of the moving charged ring covering the structure, particularly nanotube, were studied.

Interaction of plasma oscilations with charged particles intersecting a boundary of two media

In connection with the progress in modern technology of designing micro- and nanostructures the research on processes of interaction between electromagnetic oscillations and charged particles become topical. Results of this research are important both for comprehension of physics of surface phenomena occurring on media boundary and for many technical applications.

Transient radiation induced by a modulated flow of charged particles on a perfectly conducting surface with random roughness

The excitation of surface waves by a modulated electron flow in a medium whose surface has random inhomogeneities is studied. It is shown that the energy flux density of a surface wave (polariton) exhibits oscillations determined by the ratio of the period of oscillations of the electron beam and the time of flight of a charged particle in the space between the beam modulation plane and the interface between the media.

Interaction of electromagnetic oscillations with charged particle flows in nonuniform plasma-like structures

A hydrodynamic theory is developed of the interaction of electromagnetic oscillations with a monoenergetic charged particle beam propagating through a structure consisting of plasma and dielectric layers bounded by perfectly conducting planes. It is shown that, in such a system, plasma oscillations are excited due to the transformation of space charge oscillations of the particle flow into plasma oscillations at the layer boundaries. The regions of generation and decay of plasma oscillations are determined.

Energy Losses of a Charged Particle due to Excitation of Helicons in Plasma-Like Media

We study the energy lost by a particle moving along the helical line in a static magnetic field due to Vavilov–Cherenkov radiation of volume and surface helicons. It is found that the energy losses related to excitation of volume helicons are equivalent to the energy losses of a magnetic moment created due to the charge rotation. The magnetic moment moves at a constant velocity along the magnetic field. It is shown that collisionless damping of volume helicons in plasmas is based on the Cherenkov radiation of magnetic moment. Radiation of surface helicons by a particle does not correspond to the energy losses of a moving magnetic moment. This is related to the fact that not only magnetic (H) waves but also electric (E) waves contribute to the excitation of surface helicons, which leads to an increase in the energy losses of a particle.

Surface Plasma Waves at a Rough Interface of a Solid

The dispersion law for surface polaritons in an inhomogeneous plasma is obtained and studied. The plasma is formed by surface electron states at the interface of a solid under conditions where the irregularity scale is much greater than the wavelength. It is shown that the irregularity of the plasma results in spatial dispersion of surface electrostatic oscillations.