ELECTRONIC RAMAN-SCATTERING ON MODULATION-DOPED GAAS QUANTUM-WELLS - CONDUCTION-BAND STRUCTURE AND COLLECTIVE EFFECTS

We report on a detailed analysis of electronic Raman scattering result s in modulation doped single quantum wells. We illustrate thereby the great power of this technique to get a detailed characterization of th e electron density distribution and the band structure in doped hetero structures. We report in particular on a recent observation, for first time directly by spectroscopy, of the spin splitting of the conductio n band of GaAs due to the lack of inversion symmetry.