Effect of donor impurity dislocation in elliptical quantum rings

We investigate the effect of an off-center donor impurity on the electronic properties of a two-dimensional quantum ring with a deformed geometrical structure in the form of an ellipse. It is shown that the dislocation of impurity from the center of elliptical quantum ring opens sizable gaps in the energy spectrum and largely deforms the eigenenergies near the ground state. As a result, the Aharonov–Bohm oscillations are quenched and the persistent electron current decreases intensely. Moreover, we show that the ground state energy exhibits a local extremum when the donor impurity is located on semi-minor (or -major) axis of the elliptic ring. The effects of the eccentricity of elliptical ring on the energy spectra and persistent current are also studied.