TRANSITION ENERGIES OF D- CENTERS IN A SUPERLATTICE

We study a negative-donor center (D-) in a GaAs/AlGaAs superlattice in high magnetic fields along the growth axis. The energy levels of the D- states are calculated by a variational approach using a trial wave function which (1) includes electron-electron (e-e) correlation for the superlattice case, (2) with, and (3) without e-e correlation for the situation of a quantum well (QW). Polaron effects are included within second-order perturbation theory. A detailed comparison is made of the calculated transition and binding energies with the measured data of Huant et al. [4]. We found that these experimental results should be interpreted as the transition energy between two D- states.