Electrostatic Langmuir and SEAWs in spin polarized plasma double layer

TL;DR

This paper develops a quantum hydrodynamic model for electrostatic waves in double-layer 2DEGs, revealing new Langmuir-like and spin-electron acoustic waves influenced by quantum effects and spin dynamics.

Contribution

It introduces a comprehensive model accounting for spin separation and quantum effects, predicting new wave modes in double-layer 2DEGs.

Findings

Identification of two Langmuir-like waves with interference patterns in the classical regime.

Discovery of four wave modes in the quantum regime, including spin-electron acoustic waves.

Analysis of the quantum Bohm potential's influence on wave spectra.

Abstract

The quantum hydrodynamic model of the electrostatic waves in the two parallel layers of two dimensional electron gases (2DEGs) is developed. It is considered for two regimes: classic regime and quantum regime with the separate spin evolution. Two Langmuir-like waves are found in classic case which have an interference-like pattern in the frequency dependence on concentration $\omega^{2}\sim(n_{01}+n_{02}\pm2\sqrt{n_{01}n_{02}})$. They appear instead of two 2D Langmuir waves in noninteracting 2DEGs. The spectrum of four waves is found in the quantum regime. Two extra waves are related to the separate spin evolution and associated to the spin-electron acoustic waves. The influence of the quantum Bohm potential is considered either.