Dresselhaus spin-orbit interaction in the p-AlGaAs/GaAs/AlGaAs structure with a square quantum well: Surface Acoustic Waves Study

TL;DR

This study investigates the Dresselhaus spin-orbit interaction in a high-quality p-AlGaAs/GaAs/AlGaAs quantum well using acoustic methods, revealing small spin-orbit splitting governed by the Dresselhaus mechanism through analysis of conductance oscillations.

Contribution

The paper provides the first detailed analysis of spin-orbit interaction effects in a symmetric quantum well using acoustic measurements, identifying the Dresselhaus mechanism as the dominant source.

Findings

Spin-orbit splitting is small and governed by the Dresselhaus mechanism.

Conductance oscillations show beating patterns due to spin-orbit interaction.

Effective masses and relaxation times for holes are determined.

Abstract

The effect of spin-orbit interaction was studied in a high-quality $p$-AlGaAs/GaAs/AlGaAs structure with a square quantum well using acoustic methods. The structure grown on a GaAs (100) substrate was symmetrically doped with carbon on both sides of the quantum well. Shubnikov-de Haas-type oscillations of the ac conductance of two-dimensional holes were measured. At a low magnetic field $B <$2 T conductance oscillations undergo beating induced by a spin-orbit interaction. Analysis of the beating character made it possible to separate the conductance contributions from the two heavy holes subbands split by the spin-orbit interaction. For each of the subbands the values of the effective masses and quantum relaxation times have been determined, and then the energy of the spin-orbit interaction was obtained. The quantum well profile, as well as the small magnitude of the spin-orbit interaction, allowed us to conclude that the spin-orbit splitting is governed by the Dresselhaus mechanism.