Plasmons and magnetoplasmons in partially bounded two-layer electron systems

TL;DR

This paper analytically investigates plasmon modes in a two-layer electron system with a 2D electron system and a strip, revealing localized modes with unique dispersion properties, especially under magnetic fields.

Contribution

The study introduces an analytical framework for plasmons in a two-layer system with a strip, highlighting new gapless modes and their magnetodispersion characteristics.

Findings

Existence of localized plasmon modes near the strip.

Fundamental mode N=0 has gapless linear dispersion.

Magnetodispersion of the mode remains gapless under magnetic field.

Abstract

We have analytically studied plasmons in an electron system comprised of two spatially separated layers -- an infinite two-dimensional electron system (2DES) and a 2D strip. Our analysis reveals the existence of plasmon modes that are localized near and propagate along the strip. These modes are characterized by the wave vector in the direction of the strip, as well as the number of charge density nodes, N, across the strip. In the long-wavelength limit, the fundamental mode N=0 is found to have gapless linear dispersion. When the external perpendicular magnetic field is applied, this mode remains gapless and exhibits peculiar magnetodispersion. We analyze the correlation between our findings and the previously established results on plasmons in gated and partially gated 2DESs.