Donor binding energies in a curved two-dimensional electron system

Abstract

This work is concerned with the investigation of the binding energies and impurity states of a single donor located in a curved two-dimensional electron system with constant curvature under an electric field. Within the framework of the effective-mass approximation, we use a finite difference approach to solve the Schrödinger equation and calculate the binding energies of the ground and first excited states when a donor is at the centered and off-centered positions of the system. The simultaneous effects of the donor positions, curvature, and size of the system on the binding energies are reported. We find that the binding energies will increase dramatically when the radius of the curved system is less than the effective Bohr radius. Moreover, an applied electric field can be effectively used to control the values of the binding energies of a donor localized at some positions by tuning its directions.