Light scattering determination of subband structure and population of modulation-doped multiple quantum wells

Abstract
We show that electronic Raman scattering measurements of the plasmon dispersion in combination with calculations of the random phase approximation dielectric response and self-consistent electronic subband calculations can determine the subband structure and populations of modulation-doped GaAs/AlxGa1−xAs multiple quantum wells with multiple subband occupancy. Thus we present a contactless optical alternative to measurements of Shubnikov–de Haas oscillations for the determination of carrier concentrations. The same technique can also be applied for the characterization of parallel conduction from doped AlGaAs layers in modulation-doped heterostructures.