Light-induced shifts in the electronic and shallow-donor states in GaAs-(Ga,Al)As quantum dots

We treat the interaction of light with a spherical GaAs-(Ga,Al)As quantum dot within a dressed-band approach. The Kane band-structure scheme is used to model the GaAs bulk semiconductor and the interaction with the laser field is treated through the renormalization of the semiconductor energy gap and conduction/valence effective masses. This approach, valid far from resonances, is used to investigate the light shifts induced in the electronic and shallow on-center donor states in semiconductor quantum dots, which are shown to be quite considerable. This model calculation may be extended to include magnetic-field effects, and it is suggested that the strong localization of the electronic and impurity states due to the quantum dot and enhanced by laser confinement may prove useful for manipulation of electronic and donor states in some proposed solid-state-based quantum computers.