Properties of a dense quasi-two-dimensional electron-hole gas at high magnetic fields

Abstract

Due to the Landau quantisation in high magnetic fields, the high intensity excitation luminescence spectra in quantum wells, show a pronounced structure. By comparison with equally rich conventional low power pseudo-absorption spectra, the changes of the bandgap and the effective mass with carrier density, are directly measured. For electron-hole pair densities >10 12 cm −2 , a saturation of the bandgap renormalization, which is twice the exciton binding energy, is observed. The field dependence of the transitions shows an electron-hole pair correlated behavior of the ground state and a many-body enhancement of the effective mass for the excited states.