g-Factor anisotropy of hole quantum wires induced by the Rashba interaction

TL;DR

This study calculates the g factors in hole quantum wires, revealing that Rashba spin-orbit coupling causes anisotropy in magnetic response, especially as the wire deforms from 3D to 2D.

Contribution

It demonstrates how Rashba interaction induces g factor anisotropy in hole quantum wires and analyzes the effects of wire deformation on this phenomenon.

Findings

Perpendicular g factors are quenched by Rashba interaction at high deformations.

Parallel g factors are less affected by Rashba, leading to high anisotropy.

Low deformation wires show irregular, sample-dependent behavior.

Abstract

We present calculations of the g factors for the lower conductance steps of 3D hole quantum wires. Our results prove that the anisotropy with magnetic field orientation, relative to the wire, originates in the Rashba spin-orbit coupling. We also analyze the relevance of the deformation, as the wire evolves from 3D towards a flat 2D geometry. For high enough wire deformations, the perpendicular g factors are greatly quenched by the Rashba interaction. On the contrary, parallel g factors are rather insensistive to the Rashba interaction, resulting in a high g factor anisotropy. For low deformations we find a more irregular behavior which hints at a sample dependent scenario.