Aharonov-Bohm oscillations in p-type GaAs quantum rings

TL;DR

This study investigates phase coherent transport and Aharonov-Bohm oscillations in p-type GaAs quantum rings, revealing high-visibility oscillations and spin interference effects, advancing understanding of quantum interference in hole-based systems.

Contribution

It demonstrates clear AB oscillations and spin interference signatures in p-type GaAs quantum rings, highlighting the role of higher harmonics and spin effects in such systems.

Findings

High-visibility AB oscillations exceeding 10% in resistance

Observation of higher harmonic contributions to AB oscillations

Detection of a resistance minimum at B=0 T indicating spin interference

Abstract

We have explored phase coherent transport of holes in two p-type GaAs quantum rings with orbital radii 420 nm and 160 nm fabricated with AFM oxidation lithography. Highly visible Aharonov-Bohm (AB) oscillations are measured in both rings, with an amplitude of the oscillations exceeding 10% of the total resistance in the case of the ring with a radius of 160 nm. Beside the h/e oscillations, we resolve the contributions from higher harmonics of the AB oscillations. The observation of a local resistance minimum at B=0 T in both rings is a signature of the destructive interference of the holes' spins. We show that this minimum is related to the minimum in the h/2e oscillations.