Absence of skew scattering in two-dimensional systems: Testing the origins of the anomalous Hall effect

TL;DR

This paper demonstrates that skew scattering, a key extrinsic mechanism for the anomalous Hall effect, vanishes in certain two-dimensional systems, providing a benchmark for understanding intrinsic versus extrinsic contributions.

Contribution

It reveals the absence of skew scattering in specific 2D electron and hole systems, clarifying the origins of the anomalous Hall effect in these materials.

Findings

Skew scattering vanishes when both Rashba subbands are occupied in 2D electron systems.

Skew scattering always vanishes in the studied 2D hole gas, regardless of band filling.

The results offer a testable prediction for experimental devices and aid in distinguishing intrinsic and extrinsic effects.

Abstract

We study the anomalous Hall conductivity in spin-polarized, asymmetrically confined two-dimensional electron and hole systems, focusing on skew-scattering contributions to the transport. We find that the skew scattering, principally responsible for the extrinsic contribution to the anomalous Hall effect, vanishes for the two-dimensional electron system if both chiral Rashba subbands are partially occupied, and vanishes always for the two-dimensional hole gas studied here, regardless of the band filling. Our prediction can be tested with the proposed coplanar two-dimensional electron/hole gas device and can be used as a benchmark to understand the crossover from the intrisic to the extrinsic anomalous Hall effect.