Condensation kinetics of microcavity polaritons with scattering by phonons and polaritons

We present numerical studies of the exciton polariton condensation kinetics in microcavities for the combined action of polariton-polariton and polariton-acoustic phonon scattering both for quasi-stationary and picosecond pulse excitation, respectively. For excitations of nearly resonant polaritons mainly the polaritonpolariton scattering mechanism results in a condensation on the minimum of the lower polariton branch at relatively low areal polariton densities of the order of 10 9 –1 0 10 cm �2 . The simultaneously acting polaritonphonon scattering increases the number of condensed particles considerably by providing a heat dissipation from the polariton gas to the lattice. For nonresonant excitations at large k values the considered scattering mechanisms cannot support a polariton condensation. Above below laser threshold there exists a no polariton condensate and the polariton distribution of the noncondensed particles can be fitted by a Bose-Einstein Maxwell-Boltzmann distribution. Our results for 3 ps pulse excitation are in very good agreement with recent experimental observations of Yamamoto et al.