Weak localisation in AlGaAs/GaAs p-type quantum wells

TL;DR

This paper presents the first experimental study of weak localisation magnetoresistance in AlGaAs/GaAs p-type quantum wells with strong spin-orbit interaction, comparing results with a new diffusion theory that accounts for strong spin-orbit effects.

Contribution

It introduces a novel experimental investigation of weak localisation in systems with strong spin-orbit coupling and compares findings with a newly developed theoretical model.

Findings

Spin relaxation rates agree with theoretical expectations.

Enhanced phase breaking rate observed compared to predictions.

Experimental validation of the diffusion theory for strong spin-orbit systems.

Abstract

We have for the first time experimentally investigated the weak localisation magnetoresistance in a AlGaAs/GaAs p-type quantum well. The peculiarity of such systems is that spin-orbit interaction is strong. On the theoretical side it is not possible to treat the spin-orbit interaction as a perturbation. This is in contrast to all prior investigations of weak localisation. In this letter we compare the experimental results with a newly developed diffusion theory, which explicitly describes the weak localisation regime when the spin-orbit coupling is strong. The spin relaxation rates calculated from the fitting parameters was found to agree with theoretical expectations. Furthermore the fitting parameters indicate an enhanced phase breaking rate compared to theoretical predictions.