Impurities and geometrical effects on the electron energy spectrum of quantum rings

Abstract

We calculate the energy spectrum of semiconductor quantum rings. We consider a realistic model consisting of rings with finite sizes and barrier potential and take into account an external magnetic field applied perpendicularly to those structures. The solutions of the Schr\"odinger equations are found using an evolution method not limited to small perturbations. The magnetic field leads to the Aharonov-Bohm (AB) oscillations, which are strongly dependent on the presence of static defects. We consider charged impurities and interface roughness, which break the cylindrical ring symmetry and can strongly affect, or even destroy, the AB oscillations.