Gate voltage control over spin relaxation length

TL;DR

This paper demonstrates that applying a gate voltage to a high mobility GaAs/AlGaAs 2DEG channel can electrically tune the ballistic spin resonance, enabling control over spin relaxation length for potential spin logic applications.

Contribution

It introduces a novel method to electrically control spin relaxation length via gate-tuned ballistic spin resonance in a 2DEG channel.

Findings

Gate voltage tunes electron velocity and bouncing frequency.

Resonant suppression of spin relaxation length observed.

Electrical control of spin logic demonstrated.

Abstract

Spin currents in channels of a high mobility GaAs/AlGaAs two-dimensional electron gas are generated and detected using spin-polarized quantum point contacts. We have recently shown that the relaxation length of spin currents is resonantly suppressed when the frequency at which electrons bounce between channel walls matches the Larmor frequency. Here we demonstrate that a gate on top of the channel tunes such ballistic spin resonance by tuning the velocity of electrons and hence the bouncing frequency. These findings demonstrate a new mechanism for electrical control of spin logic circuits.