Anisotropic polariton scattering and spin dynamics of cavity polaritons

We describe the spin-dynamics of exciton–polaritons in semiconductor microcavities in the strong coupling regime. Using the Liouville equation for the spin-density matrix in the Born–Markov approximation we obtain kinetic equations taking into account polariton–acoustic phonon and polariton–polariton scattering. We describe both the ‘polariton laser’ regime (non-resonant excitation) and ‘optical parametric oscillator’ regime (resonant excitation at the magic angle). We obtain a good agreement with experimental data on the dynamics of polarization of light emitted by microcavities.