Quantum critical regime in a quadratically-driven nonlinear photonic lattice

Understand

We study an array of coupled optical cavities in 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.