Satellite structures in the spectral functions of the two-dimensional electron gas in semiconductor quantum wells: A GW plus cumulant study

We present theoretical calculations for the spectral functions and single-particle densities of states of the two-dimensional electron gas in semiconductor quantum wells at different electron densities using the GW plus cumulant method. We compare our results to GW only calculations and find significant differences in the description of the satellites between the two theories: While GW theory predicts the existence of a plasmaron excitation, no such excitation is found in GW plus cumulant theory. We compare our results to experimental tunneling spectra from semiconductor quantum wells and find good agreement for the satellite properties.