Polariton laser: thermodynamics and quantum kinetic theory
Cavity exciton–polaritons are considered to be two-dimensional weakly interacting true bosons. We analyse their thermodynamic properties and show that they can exhibit local condensation or Kosterlitz–Thouless phase transition towards superfluidity, so that polariton lasing can be achieved. The dynamical evolution of the condensate in a non-resonantly pumped cavity is described by a quantum kinetic formalism. The distribution function of polaritons is described by a semi-classical Boltzmann equation. A master equation for the ground-state density matrix is derived in the framework of the Born–Markov approximation. The dynamics of the ground-state population and its coherence are deduced.