Electron-Hole Correlation in Quantum Dots under a 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.