Spin interferometry in anisotropic spin-orbit fields

TL;DR

This paper investigates how anisotropic spin-orbit fields in 2DEG systems influence quantum transport, revealing resistance anisotropies and topological transitions that can be detected through resistance measurements.

Contribution

It demonstrates the impact of combined Rashba and Dresselhaus SO couplings on resistance anisotropy and topological transitions in mesoscopic rings.

Findings

Resistance anisotropy depends on Zeeman field direction.

Rashba strength can invert resistance response.

Topological transition affects geometric phase switching.

Abstract

Electron spins in a two-dimensional electron gas (2DEG) can be manipulated by spin-orbit (SO) fields originating from either Rashba or Dresselhaus interactions with independent isotropic characteristics. Together, though, they produce anisotropic SO fields with consequences on quantum transport through spin interference. Here we study the transport properties of modelled mesoscopic rings subject to Rashba and Dresselhaus [001] SO couplings in the presence of an additional in-plane Zeeman field acting as a probe. By means of 1D and 2D quantum transport simulations we show that this setting presents anisotropies in the quantum resistance as a function of the Zeeman field direction. Moreover, the anisotropic resistance can be tuned by the Rashba strength up to the point to invert its response to the Zeeman field. We also find that a topological transition in the field texture that is associated with a geometric phase switching is imprinted in the anisotropy pattern. We conclude that resistance anisotropy measurements can reveal signatures of SO textures and geometric phases in spin carriers.