Rota, RiccardoMinganti, FabrizioCiuti, CristianoSavona, Vincenzo2019-06-182019-06-182019-06-182019-03-2110.1103/PhysRevLett.122.110405https://infoscience.epfl.ch/handle/20.500.14299/157654WOS:000461923000001We study an array of coupled optical cavities in the presence of two-photon driving and dissipation. The system displays a critical behavior similar to that of a quantum Ising model at finite temperature. Using the corner-space renormalization method, we compute the steady-state properties of finite lattices of varying size, both in one and two dimensions. From a finite-size scaling of the average of the photon number parity, we highlight the emergence of a critical point in regimes of small dissipations, belonging to the quantum Ising universality class. For increasing photon loss rates, a departure from this universal behavior signals the onset of a quantum critical regime, where classical fluctuations induced by losses compete with long-range quantum correlations.Physics, MultidisciplinaryPhysicsphase-transitioncritical-behaviorsuperfluidstatesatomslightgastext::journal::journal article::research article