Terahertz radiation-induced conductivity, Kerr and Faraday angles, and spin textures in a two-dimensional electron gas with spin-orbit coupling subjected to a high magnetic field and periodic potential

TL;DR

This paper investigates how terahertz radiation affects conductivity, optical rotation, and spin textures in a two-dimensional electron gas with strong spin-orbit coupling under high magnetic fields and periodic potentials, revealing peaks at inter-subband transition frequencies.

Contribution

It introduces a detailed analysis of terahertz-induced effects on conductivity, Kerr and Faraday angles, and spin textures in a spin-orbit coupled 2D electron gas under magnetic and periodic potentials, providing new experimental insights.

Findings

Conductivity peaks at inter-subband transition frequencies.

Kerr and Faraday rotation angles can be used to probe the electron gas.

Radiation-induced spin textures with observable in-plane and out-of-plane components.

Abstract

The terahertz radiation-induced conductivity and dielectric polarization tensors as well as the Faraday and Kerr rotation angles and the non-equilibrium spin textures are studied for two-dimensional electron gas with strong spin-orbit coupling subjected to high magnetic field and to tunable periodic potential of a two-dimensional gated superlattice. It is found that both real and imaginary parts of the frequency-dependent induced conductivity approach maximum values with sharp and detectable peaks at frequencies corresponding to the inter-subband transitions between spin-split magnetic subbands. The observed properties of the conductivity tensor frequency dependence are applied for the description of the Kerr and Faraday rotation angles which can be used as another experimental tool for describing the electron gas in periodic structures with significant spin-orbit coupling. The formation of radiation-induced spin textures is predicted having both in-plane and out-of-plane components with space distribution scale comparable to the superlattice cell size which can be observed experimentally.