MAGNETOOPTICS OF ELECTRON-GASES CONFINED IN GAAS QUANTUM DOTS

Photoluminescence spectroscopy has been used to probe the occupied ele ctron states below the Fermi energy of zero-dimensional electron syste ms in both zero and finite magnetic fields. The arrays of modulation-d oped quantum dots investigated were fabricated by reactive-ion etching of Al0.3Ga0.7As/GaAs heterojunctions with a delta-layer of Be present in the GaAs at 200 Angstrom from the interface in order to improve lu minescence efficiency. We show that the low magnetic field dispersion (B < 8 T) of the acceptor recombination line is directly related to th e magnetic field dependence of the total ground state energy of intera cting electrons in the quantum dots. (C) 1997 Elsevier Science Ltd. Al l rights reserved.