Electron-hole correlation in quantum dots under high magnetic field (up to 45 T)

The influence of the direct and exchange Coulomb interaction on Landau level formation in strain induced quantum dots has been studied by high-field (45 T) magnetoluminescence and by many-electron many-hole Hartree-Fock calculations. The Darwin Fock states of the dots are found to merge into a unique Landau level at very high fields with a considerable reduction in the total diamagnetic shift due to the enhanced electron-hole correlation caused by the increased degeneracy of the state. We calculate a 50% reduction of the diamagnetic shift as a result of direct and exchange Coulomb interaction in the squeezed carrier states, in excellent agreement with the experimental findings.