Gate-controlled spin-orbit interaction in a parabolic GaAs/AlGaAs quantum well

TL;DR

This paper investigates how gate voltages can control the Rashba spin-orbit interaction in a GaAs/AlGaAs quantum well, revealing tunability of spin precession and anisotropy in spin dephasing.

Contribution

It demonstrates the electrical tunability of Rashba spin splitting and characterizes the weak Dresselhaus component in a parabolic quantum well.

Findings

Rashba spin splitting can be effectively tuned by gate biases.

Dresselhaus splitting remains weak and nearly unaffected by gating.

Zero Rashba splitting correlates with vanishing spin-dephasing anisotropy.

Abstract

We study the tunability of the spin-orbit interaction in a two-dimensional electron gas with a front and a back gate electrode by monitoring the spin precession frequency of drifting electrons using time-resolved Kerr rotation. The Rashba spin splitting can be tuned by the gate biases, while we find a small Dresselhaus splitting that depends only weakly on the gating. We determine the absolute values and signs of the two components and show that for zero Rashba spin splitting the anisotropy of the spin-dephasing rate vanishes.