Effects of hydrogenic impurity and external fields on the optical absorption in a ring-shaped elliptical quantum dot

In this work, the effects of the hydrogenic impurity, electric and magnetic fields on the optical absorption of a typical GaAs/AlGaAs ring-shaped elliptical quantum dot are investigated. Energy eigenvalues and wave functions are calculated using the three-dimensional finite element method, and optical absorption is obtained using the density matrix approach. For the impurity located at the center of the quantum dot, results show that the optical absorption increases (decreases) with increasing electric (magnetic) field. Results also indicate that the off-center hydrogenic impurity considerably reduces the optical absorption.