Many-body effects in photoluminescence of a two-dimensional electron gas in high magnetic field

The behaviour of a two-dimensional electron gas has been studied in a series of modulation doped quantum wells of the type In0.53Ga0.47As/InP with different electron densities. The low energy sidebands in the optical emission spectra in high magnetic field due to many-body effects have been investigated. In a sample with a high electron density the first shake-up sideband is followed up to 20 T, where it reappears after crossing with phonon replicas. Its intensity profile in high magnetic field confirms previous interpretations on the filling factor dependence. In a sample with a lower electron density, polarization measurements illustrated the emptying of the higher spin state in the first Landau level, reaching a high degree of polarization at a filling factor below one. (C) 1998 Elsevier Science B.V. All rights reserved.