Variational calculation of polarization of quantum-well photoluminescence

We calculate for the first time the circular polarization of GaAs/Ga_1-x{Al}ₓ$As quantum-well photoluminescence taking into account the true nonparabolic valence-band structure. Versus the excitation energy, we find high positive polarization for the transition n=1 heavy-hole--to--conduction-band transition and negative polarization at the onset of n=1 light-hole--to--conduction-band transition in qualitative agreement with experiments. We also study the Gay{In}_{1{{-}}y}$As/InP system and predict no negative polarization in this case.