The role of surface roughness on the electron confinement in semiconductor quantum rings

The electron energy spectrum of GaAs/Al0.30Ga0.70AsGaAs/Al0.30Ga0.70As quantum rings under applied magnetic fields is calculated, taking into account the existence of rough interfaces between materials. The Schrödinger equation, within the effective mass approximation, is solved in a realistic model, not limited to small perturbations. Our numerical results show that the existence of roughness on the ring surface modifies significantly the electron confinement energy, lifts the degeneracy of the electron angular momentum transition points of the Aharonov–Bohm oscillations, and in some special cases, it can even suppress the ground state energy oscillations.