High temperature gate control of quantum well spin memory

TL;DR

This study demonstrates that applying high electric fields to GaAs/AlGaAs quantum wells significantly modulates spin relaxation times, enabling voltage-controlled spin memory with high electron mobility at room temperature.

Contribution

It provides experimental evidence of electric field control over spin relaxation in quantum wells, linking Rashba effect calculations to observed spin dynamics.

Findings

Spin relaxation rate increases ten-fold with electric field at 170 K.

Spin relaxation remains nearly constant below 20 kV/cm.

Voltage gating can achieve spin memory times over 3 ns with high mobility.

Abstract

Time-resolved optical measurements in (110)-oriented GaAs/AlGaAs quantum wells show a ten-fold increase of the spin-relaxation rate as a function of applied electric field from 20 to 80 kV cm-1 at 170 K and indicate a similar variation at 300 K, in agreement with calculations based on the Rashba effect. Spin relaxation is almost field-independent below 20 kV cm-1 reflecting quantum well interface asymmetry. The results indicate the achievability of voltage-gateable spin-memory time longer than 3 ns simultaneously with high electron mobility.