MANIFESTATION OF EXCITONIC EFFECTS IN THE MAGNETO-OSCILLATIONS OF THEINTENSITY OF THE RECOMBINATION RADIATION OF 2D ELECTRONS

A study is made of the temperature dependence of the magnetooscillatio ns of the recombination radiation of 2D electrons from the photoexcite d size-quantization subband in an isolated GaAs/AlGaAs quantum well. I t is shown that at high temperatures (T> 10 K) the period of the oscil lations is determined by the ratio of the intersubband energy splittin g and the sum of the electron and hole cyclotron energies. It is found that as the temperature decreases (T<5 K), a new series of oscillatio ns (with the same period but with a larger phase shift), which are ass ociated with the appearance of excitonic states under the Landau level s, appears. (C) 1996 American Institute of Physics.