Observation of the Crossover from Photon Ordering to Delocalization in Tunably Coupled Resonators

Understand

Networks of nonlinear resonators offer intriguing perspectives as quantum simulators for non-equilibrium many-body phases of driven-dissipative systems.

• Here, we employ photon correlation measurements to study the radiation fields emitted from a system of two superconducting resonators, coupled nonlinearly by a superconducting quantum interference device (SQUID).
• We apply a parametrically modulated magnetic flux to control the linear photon hopping rate between the two resonators and its ratio with the cross-Kerr rate.
• When increasing the hopping rate, we observe a crossover from an ordered to a delocalized state of photons.