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

摘要

We study the role of different orientations of an applied magnetic field aswell as the interplay of structural asymmetries on the characteristics ofeigenstates in a quantum ring system. We use a nearly analytical modeldescription of the quantum ring, which allows for a thorough study ofelliptical deformations and their influence on the spin content and Berry phaseof different quantum states. The diamagnetic shift and Zeeman interactioncompete with the Rashba spin-orbit interaction, induced by confinementasymmetries and external electric fields, to change spin textures of thedifferent states. Smooth variations in the Berry phase are observed forsymmetric quantum rings as function of applied magnetic fields. Interestingly,we find that asymmetries induce nontrivial Berry phases, suggesting thatdefects in realistic structures would facilitate the observation of geometricphases.