Manipulation of the Spin Memory of Electrons in n-GaAs

TL;DR

This paper demonstrates optical control over electron spin relaxation times in n-GaAs, showing how laser frequency adjustments can significantly alter spin dynamics through hyperfine interactions and electron depletion.

Contribution

It introduces a method to manipulate electron spin relaxation times in n-GaAs using optical techniques and provides both experimental and theoretical insights into the underlying mechanisms.

Findings

Spin relaxation time varies from 300 ns to 5 ns.

Laser frequency influences electron depletion and spin relaxation.

Hyperfine interaction with nuclei governs spin relaxation.

Abstract

We report on the optical manipulation of the electron spin relaxation time in a GaAs based heterostructure. Experimental and theoretical study shows that the average electron spin relaxes through hyperfine interaction with the lattice nuclei, and that the rate can be controlled by the electron-electron interactions. This time has been changed from 300 ns down to 5 ns by variation of the laser frequency. This modification originates in the optically induced depletion of n-GaAs layer.