VARIATIONAL STUDIES OF THE QUASI-2-DIMENSIONAL D(-)CENTRE IN MAGNETIC-FIELDS

We present a simple variational scheme for calculating the binding ene rgies and the lowest dipole optical transition energies of D- impuriti es in the middle of quantum wells at moderate and high magnetic fields . The objective was to make the model and the method as simple as poss ible but to be able to explain many of the experimental features obser ved. The simple form of the electronic wavefunctions used enables phys ical insight into the properties of the D- system in quantum wells. Th e scheme, based on the parabolic approximation for the conduction band , gives results compatible with those of more sophisticated approaches . A simple renormalization procedure makes the results compatible also with the experimental results for GaAs quantum wells for which band n on-parabolicity proved to be important. The energies for the lowest di pole optical transitions were calculated for a broad range of magnetic fields and well widths.