Influence of Coulomb and exchange interaction on quantum dot magnetoluminescence up to B=45 T

The influence of the direct and exchange Coulomb interaction on Landau leve l formation in strain induced QD has been studied by high-field (45 T) magn eto-luminescence measurements and by many-electron many-hole Hartree-Fock c alculations. At high magnetic fields the degeneracy of the QD electron and hole ground states is increased as several zero-field eigenstates merge int o the lowest Landau level. This leads to removal of the state filling and a ccordingly in high magnetic field the QD luminescence is emitted from the l owest Landau level. Using a generalization of Koopmans theorem for electron -hale many particle systems, we have studied the enhancement of the direct and exchange Coulomb interaction in squeezed carrier states. The results sh ow that for 6 to 8 electron-hole pairs the direct and exchange interaction both reduce the diamagnetic shift by 15 to 25 %.