Donor impurity on-center and off-center in multilayered quantum wires in the presence of magnetic field

Abstract

The binding energies of a hydrogenic impurity located at the center and off-center of a multilayered quantum wire (MLQW) in the presence of magnetic field are studied within the framework of the effective-mass approximation. The MLQW consists of a GaAs core wire coated by a AlxGa1−xAs cylindrical shell and embedded in the bulk AlyGa1−yAs. A variational trial wave function is proposed. It is found for a small wire radius that the ground state binding energy of a hydrogenic impurity located at the center of a MLQW behaves very differently from that of a single-layered quantum wire (SLQW). The calculation shows that the binding energy depends on the potential profiles, potential barrier height, impurity position, shell thickness, magnetic field, and the difference between the Al concentration contained in the shell and bulk regions. Our trial function is also able to reproduce the binding energies of a hydrogenic impurity located at the center of a SLQW, good agreement with the previous results is obtained.