The Aharonov-Bohm oscillations and energy spectrum in two-dimensional elliptical quantum ring nanostructures

Based on the finite element method, we present a numerical study of the Aharonov-Bohm (AB) oscillations and electronic energy spectrum for the system of a two-dimensional elliptical quantum ring (EQR) nanostructure pierced by a static magnetic flux phi in the presence of local charge impurities. Strong changes are observed in the energy spectrum and in the amplitude of the AB oscillations depending on both the geometrical parameters of the EQR and the strengths, locations and screening of impurities embedded in the system. Energy gaps are opened at the integer values of phi due to elliptical confinement, while the opening of the gaps at the half-integer values of phi depends on the location of impurities. Impurities can shift the low-lying energy levels in various ways depending on their azimuthal locations.