Effects of the heavy- and light-hole mixing in the exciton dynamics in semiconductor quantum wells

We present the calculation of the low temperature exciton bimolecular forma tion rate in quantum wells through acoustic phonon scattering taking into a ccount the heavy- and light-hole mixing in the hole and exciton states. We observe a decrease in the exciton formation rate compared to the parabolic approximation. For symmetric quantum wells, the hole-subband mixing allows a finite probability of scattering involving the change of parity. This ope ns a channel for spin-flip transitions during the exciton formation process .