BAND MIXING EFFECTS IN QUANTUM-WELL MAGNETOEXCITONS

The influence of intersubband mixing in quantum wells of semiconductor s with zinc-blende structure is studied both experimentally and theore tically. A multiband magnetoexciton model is described which takes int o account k.p mixing between valence subbands and the effective Coulom b interaction for an arbitrary confinement potential shape. Theoretica l results reproduce very well the photoluminescence excitation spectra of GaAs/AlGaAs single quantum wells of various widths. In particular, the characteristic avoided crossing between the lowest light-hole exc iton Landau level and excited heavy-hole exciton Landau level occurrin g at sigma(-) polarization is accurately described by our theory.