Spin dynamics of polaritons in II-VI microcavities:detuning dependence

摘要

We have studied the polarization of the light emitted by asemiconductor microcavity as a function of the detuning between thecavity-mode and the exciton. The time dependence of the polarization,which represents the spin dynamics of the polaritons, shows a very richand novel behaviour in this non-linear regime, as compared to that underlow excitation conditions. The sign of the polarization is stronglydependent on the cavity-exciton detuning (δ = EC - EX): it is positive for δ> 0 and negative for δ < 0. The negative polarization is directly relatedwith an energy splitting between the σ +- and σ –-polarised components ofthe emission, which appears when the excitation density drives the cavityinto the non-linear regime.