Fractional quantum Hall states of photons in an array of dissipative   coupled cavities
  We report a theoretical study of the collective optical response of a two-dimensional array of nonlinear cavities in the impenetrable photon regime under a strong artificial magnetic field. Taking advantage of the non-equilibrium nature of the photon gas, we propose an experimentally viable all-optical scheme to generate and detect strongly correlated photon states which are optical analogs of the Laughlin states of fractional quantum Hall physics. 
R. O. Umucalilar, I. Carusotto
cond-mat.quant-gas