SHELL STRUCTURE AND ELECTRONIC EXCITATIONS OF QUANTUM DOTS IN A MAGNETIC-FIELD PROBED BY INELASTIC LIGHT-SCATTERING

Inelastic light scattering experiments on deep-etched GaAs/AlGaAs modu lation doped quantum dots in a magnetic field are reported. The Raman measurements at large in-plane wave vector transfer reveal a multicomp onent excitation spectrum of the many-electron quantum dots. Observed transitions split with the magnetic field. The experimental results ar e interpreted in terms of the calculated excitation spectrum in the Ha rtree approximation. The results reveal an electronic shell structure of quantum dots and a low energy excitation due to a Landau-like band crossing the Fermi level with increasing magnetic field.