Electronic excitations in semiconductors with doping superlattices

Electron-hole excitation energies in the subband structure of semiconductors with doping superlattices are obtained from a discussion of the Bethe-Salpeter equation in a local representation. For two examples representing different subband structures due to different design parameters of the superlattice we present numerical results for intersubband excitations (spin-flip and non-spin-flip) with the wave vector along the superlattice axis. We include in the interaction term of the Bethe-Salpeter equation the electron-hole attraction and its associated exchange counterpart which corresponds to the resonant screening.