Remote and spatially separated D- centers in quasi-two-dimensional semiconductor structures

The electronic structure, binding energy, and correlation functions of three different spatial configurations of D- centers in GaAs-based semiconductor structures are studied using a numerical technique that solves the two-electron Schrodinger equation for such systems. We compare our results for the quantum well D-w(-) with experimental data and variational and diffusion Monte Carlo calculations: We demonstrate the existence of the spatially separated D-s(-) center as a bound state, even in the regime of very low magnetic fields, and find interesting anticrossings among the energy levels in its electronic structure, which underlie a spectrum composition df a D-0 donor center and a free electron in a magnetic field. For the remote D-r(-) center we find that strong electron-electron correlations can give rise to magnetic-field-induced angular-momentum transitions, and as the magnetic field increases, these correlations weaken, while eventually the system magnetically evaporates approaching the classical unbound regime.