# Spatial dispersion of the high-frequency conductivity of two-dimensional electron gas subjected to a high electric field: collisionless case

## TL;DR

This paper analyzes the spatial dispersion of high-frequency conductivity in a 2D electron gas under high electric fields, revealing unique non-reciprocal and oscillatory behaviors with implications for THz applications.

## Contribution

It provides a detailed theoretical analysis of the spatial dispersion of dynamic conductivity in high-field 2DEG, highlighting novel non-reciprocal and oscillatory effects.

## Key findings

- Strong non-reciprocal dispersion at finite wavevector
- Oscillatory behavior of high-frequency conductivity
- Presence of frequency regions with negative conductivity

## Abstract

We present the analysis of high-frequency (dynamic) conductivity with the spatial dispersion, $\sigma (\omega, {\bf q})$, of two-dimensional electron gas subjected to a high electric field. We found that at finite wavevector, ${\bf q}$, and at high fields, the high-frequency conductivity shows following peculiarities: strong non-reciprocal dispersion; oscillatory behavior; a set of frequency regions with negative $\sigma'$; non-exponential decay of $\sigma'$ and $\sigma''$ with frequency (opposite to the Landau damping mechanism). We illustrate the general results by calculations of spectral characteristics of particular plasmonic heterostructures on the basis of III-V semiconductor compounds. We conclude that the detailed analysis of the spatial dispersion of the dynamic conductivity of 2DEG subjected to high electric fields is critically important for different THz applications.