Gate-controlled anisotropy in Aharonov-Casher spin interference: signatures of Dresselhaus spin-orbit inversion and spin phases

TL;DR

This paper demonstrates how gate-controlled Rashba and Dresselhaus spin-orbit interactions induce anisotropic spin interference effects in semiconductor rings, revealing new ways to manipulate spin phases electrically and magnetically.

Contribution

It provides experimental evidence of gate-tunable anisotropy and inversion in Dresselhaus SOI within Aharonov-Casher interferometry, supported by theoretical and numerical analysis.

Findings

Gate-controlled anisotropy in AC resistance observed

Identification of Dresselhaus SOI sign change via electrical tuning

Manipulation of spin phases through electric and magnetic controls

Abstract

The coexistence of Rashba and Dresselhaus spin-orbit interactions (SOIs) in semiconductor quantum wells leads to an anisotropic effective field coupled to carriers' spins. We demonstrate a gate-controlled anisotropy in Aharonov-Casher (AC) spin interferometry experiments with InGaAs mesoscopic rings by using an in-plane magnetic field as a probe. Supported by a perturbation-theory approach, we find that the Rashba SOI strength controls the AC resistance anisotropy via spin dynamic and geometric phases and establish ways to manipulate them by employing electric and magnetic tunings. Moreover, assisted by two-dimensional numerical simulations, we identify a remarkable anisotropy inversion in our experiments attributed to a sign change in the renormalized linear Dresselhaus SOI controlled by electrical means, which would open a door to new possibilities for spin manipulation.