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 modulation doped quantum dots in a magnetic field are reported. The Raman measurements at large in-plane wave vector transfer reveal a multicomponent excitation spectrum of the many-electron quantum dots. Observed transitions split with the magnetic field. The experimental results are interpreted in terms of the calculated excitation spectrum in the Hartree 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.