OSCILLATOR STRENGTH OF THE E1HH1 EXCITONIC-TRANSITION AS A FUNCTION OF MAGNETIC-FIELD IN MODULATION-DOPED GAALAS GAAS QUANTUM-WELL/

We present an experimental and theoretical investigation of the oscill ator strength of E1HH1 excitonic transition in the presence of the ext ernal magnetic field in thick GaAlAs/GaAs quantum well. We observe a d ramatic increase of the oscillator strength given by a factor 6 when t he magnetic field increases from 0 to 8 Tesla. The variational calcula tion performed in models of exciton confinement as a whole particle, a nd independent electron and hole quantization demonstrates the substan tial magnetic field induced squeezing of the exciton wave function in a QW plane, which causes an increase of the oscillaltor strength in go od agreement with experimental data.