Aharonov-Casher effect in quantum ring ensembles

TL;DR

This paper investigates electron transport in quantum ring ensembles with Rashba spin-orbit interaction, revealing slow conductance oscillations due to spin-orbit-induced level beating, aligning with experimental observations.

Contribution

It introduces an ensemble averaging approach to explain conductance oscillations in quantum rings, offering a new interpretation of the Aharonov-Casher effect in such systems.

Findings

Predicts slow conductance oscillations as a function of Rashba interaction.

Shows ensemble averaging explains experimental results.

Provides a different interpretation from the single-ring Aharonov-Casher effect.

Abstract

We study the transport of electrons through a single-mode quantum ring with electric field induced Rashba spin-orbit interaction that is subjected to an in-plane magnetic field and weakly coupled to electron reservoirs. Modelling a ring array by ensemble averaging over a Gaussian distribution of energy level positions, we predict slow conductance oscillations as a function of the Rashba interaction and electron density due to spin-orbit interaction-induced beating of the spacings between the levels crossed by the Fermi energy. Our results agree with experiments by Nitta c.s., thereby providing an interpretation that differs from the ordinary Aharonov-Casher effect in a single ring.