Spin relaxation in diluted magnetic semiconductors. GaMnAs as example

TL;DR

This paper investigates spin relaxation mechanisms in diluted magnetic semiconductors, specifically GaMnAs, combining theoretical modeling with experimental measurements to understand how magnetic impurities influence spin dynamics above the Curie temperature.

Contribution

It introduces a theoretical model for impurity spin relaxation mediated by mobile carriers and validates it with experimental data on GaMnAs.

Findings

Spin relaxation rate increases with temperature in ferromagnetic samples.

The relaxation rate approaches that of paramagnetic samples at higher temperatures.

The model explains the temperature dependence of spin relaxation in diluted magnetic semiconductors.

Abstract

We report on study of magnetic impurities spin relaxation in diluted magnetic semiconductors above Curie temperature. Systems with a high concentration of magnetic impurities where magnetic correlations take place were studied. The developed theory assumes that main channel of spin relaxation is mobile carriers providing indirect interactions between magnetic impurities. Our theoretical model is supported by experimental measurements of manganese spin relaxation time in GaMnAs by means of spin-flip Raman scattering. It is found that with temperature increase spin relaxation rate of ferromagnetic samples increases and tends to that measured in paramagnetic sample.