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

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.