National Research Council of Canada. NRC Institute for Microstructural Sciences
We study the effect of free carriers on photoluminescence from modulation-doped self-assembled quantum dots. Exact diagonalization studies of up to N=8 electrons and a single exciton in InAs self-assembled dots, and a Hartree-Fock calculations for up to N=20 electrons, are carried out. The total spin and total angular momentum are found to oscillate with the number of electrons. The photoluminescence spectrum is calculated and the band-gap renormalization in zero-dimensional systems is discussed. The tendency of electrons in degenerate, partially filled electronic shells to maximize the total spin leads to a strong dependence of the spectrum on the number of electrons N, the magnetic field B, and the polarization of light.