Coherent and incoherent aspects of polariton dynamics in semiconductor   microcavities
  The interaction between coherent polaritons and incoherent excitons plays an important role in polariton physics. Using resonant pump-probe spectroscopy with selective excitation of single polariton branches, we investigate the different dephasing mechanisms responsible for generating a long-lived exciton reservoir. As expected, pumping the upper polariton results in a strong dephasing process that leads to the generation of a long lived reservoir. Unexpectedly, we observe an efficient reservoir creation while exciting only the lower polariton branch when the detuning is increased towards positive detuning. We propose a simple theoretical model, the polaritonic Bloch equations, to describe the dynamics of the system. 
N. Takemura and M. D. Anderson and S. Biswas and M. Navadeh-Toupchi   and D. Y. Oberli and M. T. Portella-Oberli and B. Deveaud
cond-mat.mes-hall