We have studied polariton spin dynamics in a GaAs/AlGaAs microcavity by means of polarization- and time-resolved photoluminescence spectroscopy as a function of excitation density and normal mode splitting. The experiments reveal a novel behavior of the degree of polarization of the emission, namely the existence of a finite delay to reach its maximum value. We have also found that the stimulated emission of the lower polariton branch has a strong influence on spin dynamics: in an interval of ∼150 ps the polarization changes from +100% to negative values as high as -60%. This strong modulation of the polarization and its high speed may open new possibilities for spin-based devices.
@article{arxiv.cond-mat/0003491,
title = {Spin Dynamics of Cavity Polaritons},
author = {M. D. Martin and L. Vina and J. K. Son and E. E. Mendez},
journal= {arXiv preprint arXiv:cond-mat/0003491},
year = {2009}
}