Interferences between Bogoliubov excitations in superfluids of light

Ippei Danshita, Susumu Kurihara, Shunji Tsuchiya

Christopher Gaul

Quentin Fontaine, Pierre-Élie Larré, Giovanni Lerario +7 more

Paraxial fluids of light represent an alternative platform to atomic Bose-Einstein condensates and superfluid liquids for the study of the quantum behavior of collective excitations.A key step in this direction is the precise characterization of the Bogoliubov dispersion relation, as recently shown in two experiments.However, the predicted interferences between the phonon excitations that would be a clear signature of the collective superfluid behavior have not been observed to date.Here, by analytically, numerically, and experimentally exploring the phonon phase velocity, we observe the presence of interferences between counterpropagating Bogoliubov excitations and demonstrate their critical impact on the measurement of the dispersion relation.These results are evidence of a key signature of light superfluidity and provide a characterization tool for quantum simulations with photons.

R. Y. Chiao, Jack Boyce

The Bogoliubov dispersion relation for the elementary excitations of the weakly-interacting Bose gas is shown to hold for the case of the weakly-interacting photon gas (the ``photon fluid'') in a nonlinear Fabry-Perot cavity. This relation, which is also derived by means of a linearized fluctuation analysis in classical nonlinear optics, implies the possibility of a new superfluid state of light. The theory underlying an experiment in progress to measure this dispersion relation is described, and another experiment to test the prediction of the superfluidity of this state of light is proposed.

Robert Roth, Ana María Rey, Keith R. Burnett +3 more

Katz, Gcrshnable, Rowen +1 more