Control of spin dynamics in a two-dimensional electron gas by electromagnetic dressing

TL;DR

This paper demonstrates that a high-frequency electromagnetic field can control spin relaxation in a two-dimensional electron gas with Rashba spin-orbit interaction, enabling tunable spin properties for spintronics applications.

Contribution

It provides a theoretical framework showing how electromagnetic dressing can switch spin relaxation regimes in a 2DEG, a novel approach for light-controlled spintronics.

Findings

Electromagnetic dressing can switch between Elliott-Yafet and D'yakonov-Perel' spin relaxation regimes.

The spin properties of 2DEG can be tuned by high-frequency electromagnetic fields.

The study introduces a new method for controlling spin dynamics with light.

Abstract

We solved the Schr\"odinger problem for a two-dimensional electron gas (2DEG) with the Rashba spin-orbit interaction in the presence of a strong high-frequency electromagnetic field (dressing field). The found eigenfunctions and eigenenergies of the problem are used to describe the spin dynamics of the dressed 2DEG within the formalism of the density matrix response function. Solving the equations of spin dynamics, we show that the dressing field can switch the spin relaxation in the 2DEG between the cases corresponding to the known Elliott-Yafet and D'yakonov-Perel' regimes. As a result, the spin properties of the 2DEG can be tuned by a high-frequency electromagnetic field. The present effect opens an unexplored way for controlling the spin with light and, therefore, forms the physical prerequisites for creating light-tuned spintronics devices.