The Effects of Quantum Confinement and Magnetic Fields on the Binding Energy of Hydrogenic Impurities in Low-Dimensional Systems

Abstract

Using a variational procedure within the effective-mass approximation we calculated the binding energy of a shallow hydrogenic impurity on-center located in cylindrical shape GaAS–(Ga,Al)As low-dimensional systems, such as: quantum-well, quantum-well wires, and quantum dots, considering an infinite confining potential in all surfaces of the structures. The binding energy of the ground state is calculated as function of length, radius of the structure, and intensity of a magnetic field applied in axial direction. We show that the binding energy of the impurity decreases with both the length and radius of the structure, whereas it increases with the applied magnetic field. Finally, we show that our results are in good agreement with those obtained in previous calculations in GaAs–(Ga,Al)As quantum wells, quantum-well wires and quantum dots of comparable dimensions. We consider future understanding of optical phenomena related with donor impurities in GaAs–(Ga,Al)As low-dimensional systems in which the effects of applied magnetic fields compete with the quantum confinement, must take into account these results.