Fig. 4: Evolution of the polariton state in phase space.
From: Quantum coherence of a long-lifetime exciton-polariton condensate
a–d Phase averaged Husimi distributions for excitation powers of 0.77 Pth, 1.05 Pth, 1.15 Pth and 1.35 Pth, displaying the transition from a vacuum state, characterized by a Gaussian probability distribution, to a displaced thermal state with a ring-like distribution. In case (b), the main figure only shows the condensate state distribution, the distribution of the whole recorded data set is given in the corresponding inset. e Coherent (black circles) and thermal (red diamonds) photon numbers extracted from the Husimi representations at different excitation powers. f Corresponding g(2)(0) as a function of the excitation power. g Calculated quantum coherence in dependence of the excitation power.
