Magnetoluminescence of highly excited InAs/GaAs self-assembled quantum dots

We present magnetoluminescence measurements of InAs/GaAs self-assembled quantum dots (QD's) at different excitation intensities. By applying high excitation intensities, the magnetic field evolution of the excited-state emission of QD's is revealed. A splitting of the states with a nonzero magnetic momentum is observed and the in-plane reduced electron-hole mass is determined. The experimental value is found to be in a good agreement with the theoretical predictions based on the eight-band k·p model including both strain effect and band nonparabolicity. The density dependence of the diamagnetic shift of the ground-state emission is also studied providing evidence for screening of the Coulomb interaction in QD's.