Effect of spatial dispersion on the spectrum of inter-edge magnetoplasmons in the two-dimensional heterogeneous system

TL;DR

This paper theoretically investigates how spatial dispersion affects the spectrum of inter-edge magnetoplasmons in two-dimensional electronic systems under magnetic fields, revealing oscillatory behavior of their frequency with wavevector.

Contribution

It introduces a dispersion equation for inter-edge magnetoplasmons that includes spatial dispersion of conductivity, extending previous models that neglected this effect.

Findings

IEMP frequency oscillates with wavevector due to spatial dispersion.

For long wavelengths, the dispersion matches known results.

The model accounts for weak but stepwise changes in electron concentration.

Abstract

The present paper is devoted to the theoretical study of the spectrum of low-frequency electronic density oscillations running along the boundary of two contacting two-dimensional electronic systems in the perpendicular magnetic field. For the first time, such waves were predicted in the Institute of Radio-engineering and Electronics of RAS (V.A. Volkov, S.A. Mikhailov, 1992), studied experimentally in the papers of foreign investigations and called inter-edge magnetoplasmons (IEMP). When the two-dimensional system is finite and has the half-plane shape, the internal boundary becomes external and these plasmons go over into the well-known edge magnetoplasmons. The existing theory of edge and inter-edge magnetoplasmons is built with the neglect of spatial dispersion of the conductivity. Here we attempt to derive and analyze the IEMP dispersion equation involving spatial dispersion of conductivity. The inner boundary is assumed to be a straight line at which the electron concentration changes weakly but stepwise. The jump of the diagonal conductivity is considered small compared with that of the Hall magnetoconductivity. The IEMP frequency is small compared with the cyclotron frequency. The IEMP frequency as a function of wavevector oscillates with the period determined by a ratio of electron cyclotron radius to the plasmon wavelength. For long wavelengths, the IEMP dispersion curve coincides with the known result.