Berry phase and Rashba fields in quantum rings in tilted magnetic field

TL;DR

This paper investigates how magnetic field orientation, structural asymmetries, and external influences affect the eigenstates, spin textures, and Berry phases in quantum rings, revealing that asymmetries induce nontrivial geometric phases.

Contribution

It introduces a nearly analytical model to study the effects of elliptical deformations and asymmetries on Berry phases and spin properties in quantum rings under tilted magnetic fields.

Findings

Asymmetries induce nontrivial Berry phases.

Symmetric rings show smooth Berry phase variations with magnetic field.

External electric fields and confinement asymmetries influence spin textures.

Abstract

We study the role of different orientations of an applied magnetic field as well as the interplay of structural asymmetries on the characteristics of eigenstates in a quantum ring system. We use a nearly analytical model description of the quantum ring, which allows for a thorough study of elliptical deformations and their influence on the spin content and Berry phase of different quantum states. The diamagnetic shift and Zeeman interaction compete with the Rashba spin-orbit interaction, induced by confinement asymmetries and external electric fields, to change spin textures of the different states. Smooth variations in the Berry phase are observed for symmetric quantum rings as function of applied magnetic fields. Interestingly, we find that asymmetries induce nontrivial Berry phases, suggesting that defects in realistic structures would facilitate the observation of geometric phases.