Magnetotransport in Two-Dimensional Electron Systems with Spin-Orbit Interaction

TL;DR

This paper investigates how spin-orbit interaction affects magnetotransport in 2D electron systems, revealing a modulation in conductivity that can identify spin-orbit coupling effects even at higher temperatures.

Contribution

It introduces a detailed quantum mechanical model for magnetotransport with spin-orbit interaction, predicting observable conductivity modulations beyond traditional SdH oscillations.

Findings

Modulation in conductivity due to Landau level crossing points.

Persistence of modulation at elevated temperatures.

Predictions for 1/B oscillations in superlattices.

Abstract

We present magnetotransport calculations for homogeneous two-dimensional electron systems including the Rashba spin-orbit interaction, which mixes the spin-eigenstates and leads to a modified fan-chart with crossing Landau levels. The quantum mechanical Kubo formula is evaluated by taking into account spin-conserving scatterers in an extension of the self-consistent Born approximation that considers the spin degree of freedom. The calculated conductivity exhibits besides the well-known beating in the Shubnikov-de Haas (SdH) oscillations a modulation which is due to a suppression of scattering away from the crossing points of Landau levels and does not show up in the density of states. This modulation, surviving even at elevated temperatures when the SdH oscillations are damped out, could serve to identify spin-orbit coupling in magnetotransport experiments. Our magnetotransport calculations are extended also to lateral superlattices and predictions are made with respect to 1/B periodic oscillations in dependence on carrier density and strength of the spin-orbit coupling.