EXCITON SPIN DYNAMICS AND POLARIZED LUMINESCENCE IN QUANTUM-WELLS

The time evolution of the polarized luminescence is used to provide a better understanding of the relaxation processes of excitons in quantu m wells. We established and solved a coupled set of rate equations for the exciton spin populations in which the spin relaxation mechanisms include the exchange interaction and individual spin-flip of the elect rons and holes. A time-dependent energy distribution for the excitons is used to account for the thermalization effect. The dependence of th e exchange-driven channel on a longitudinal electric field is shown to be useful in determining its relative importance among various compet ing spin relaxation channels.