EXCITONIC EFFECTS IN THE RECOMBINATION RADIATION SPECTRA OF COMPLETELY FILLED LANDAU-LEVELS OF 2-DIMENSIONAL ELECTRONS

The recombination radiation spectra of two-dimensional electrons in an asymmetrically doped GaAs/AlGaAs quantum well are investigated at dif ferent temperatures and laser-excitation energies. At low temperatures and in high magnetic fields the recombination lines of the electrons from completely filled Landau levels are split into narrow sublevels. It is shown that this fine structure of the Landau levels is due to th e presence of excitonic effects in the initial and final states of the photoexcited system. it is demonstrated that the recombination proces s is accompanied by the excitation of intersubband and cyclotron magne toplasma modes. (C) 1997 American Institute of Physics.