Extraordinary waves in two dimensional electron gas with separate spin evolution and Coulomb exchange interaction

TL;DR

This paper analyzes extraordinary waves in a two-dimensional electron gas considering separate spin evolution, Coulomb exchange interaction, and electric fields, revealing frequency decreases and negative dispersion effects.

Contribution

It introduces a hydrodynamic model including transverse electric fields and Coulomb exchange interaction for 2D electron gases with spin effects, highlighting new wave behaviors.

Findings

Frequency of Langmuir and spin-electron acoustic waves decreases due to exchange interaction.

Spin-electron acoustic wave exhibits negative dispersion at high spin polarization.

Transverse electric field contribution is small compared to longitudinal in 2D plasma.

Abstract

Hydrodynamics analysis of waves in two-dimensional degenerate electron gas with the account of separate spin evolution is presented. The transverse electric field is included along with the longitudinal electric field. The Coulomb exchange interaction is included in the analysis. In contrast with the three-dimensional plasma-like mediums the contribution of the transverse electric field is small. We show the decrease of frequency of both the extraordinary (Langmuir) wave and the spin-electron acoustic wave due to the exchange interaction. Moreover, spin-electron acoustic wave has negative dispersion at the relatively large spin-polarization. Corresponding dispersion dependencies are presented and analyzed.