Interferences between Bogoliubov excitations in superfluids of light

Year: 2020

Authors: Fontaine Q., Larré P.Y., Lerario G., Bienaimy T., Pigeon S., Faccio D., Carusotto I., Giacobino Y., Bramati A., Glorieux Q.

Autors Affiliation: Sorbonne Univ, Coll France, ENS PSL Res Univ, Lab Kastler Brossel,CNRS, F-75005 Paris, France; CY Cergy Paris Univ, CNRS, LPTM, F-95000 Cergy, France; CNR, NANOTEC Inst Nanotechnol, Via Monteroni, I-73100 Lecce, Italy; Univ Glasgow, Sch Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland; ING Consiglio Nazl Ric BEC Ctr, Via Sommar, I-38123 Povo, Italy; Univ Trento, Via Sommar, I-38123 Povo, Italy.

Abstract: 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.

Journal/Review: PHYSICAL REVIEW RESEARCH

Volume: 2 (4)      Pages from: 43297-1  to: 43297-11

More Information: This work has received funding from the French Agence Nationale de la Recherche (ANR) grant (C-FLigHT No. 138678-ANR-16-ACHN-0027 and Quantum Fluids of Light QFL grant No. ANR-16-CE30-0021) and from the European Union’s Horizon 2020 Research and Innovation Program under Grant No. 820392 (PhoQuS). Q.G. and A.B. thank the Institut Universitaire de France (IUF) for support. I.C. acknowledges support from the Provincia Autonoma di Trento.
KeyWords: Bose-einstein Condensation
DOI: 10.1103/PhysRevResearch.2.043297