Effects of dielectric screening and position dependent effective mass on donor binding energies and on diamagnetic susceptibility in a quantum well

The binding energies of a shallow hydrogenic donor in the GaAs quantum well have been calculated using five different screening functions within the effective mass approximation. Both the infinite and finite confinements are used. Though all the screening functions yield results, which are nearly the same for all well dimensions studied, it is observed that the Resta dielectric function leads to smaller binding energies for well dimensions ≤100 Å. The diamagnetic susceptibility of a hydrogenic donor has also been estimated and the results are in good agreement with the recently reported values. In addition, the position dependent effective masses are used for both confinements and the results for donor ionization energies and diamagnetic susceptibilities are shown to be appreciable for narrow well dimensions. Using the Resta dielectric function, pressure effects on donor ionization energies and diamagnetic susceptibilities are estimated for Q2D GaAs. It is found that while the ionization energies increase with pressure, |χdia| decreases with pressure.