Optically-Induced Suppression of Spin Relaxation in Two-Dimensional Electron Systems with Rashba Interaction

TL;DR

This paper demonstrates that a sequence of optical pulses can significantly suppress spin relaxation in two-dimensional electron systems with Rashba interaction, enhancing spin coherence times.

Contribution

It introduces a pulsed optical technique analogous to spin echo to control and suppress spin relaxation in 2D electron systems with Rashba interaction.

Findings

Optical pulse sequences can extend spin relaxation times.

Maximum relaxation time occurs at π-pulse sequences.

Distant pulses still effectively suppress relaxation.

Abstract

A pulsed technique for electrons in 2D systems, in some ways analogous to spin echo in nuclear magnetic resonance, is discussed. We show that a sequence of optical below-band gap pulses can be used to suppress the electron spin relaxation due to the D'yakonov-Perel' spin relaxation mechanism. The spin relaxation time is calculated for several pulse sequences within a Monte Carlo simulation scheme. The maximum of spin relaxation time as a function of magnitude/width of the pulses corresponds to $\pi$-pulse. It is important that even relatively distant pulses efficiently suppress spin relaxation.