Role of geometry in the superfluid flow of nonlocal photon fluids
Authors: Vocke D., Wilson K., Marino F., Carusotto I., Wright E.M., Roger T., Anderson B.P., Ohberg P., Faccio D.
Autors Affiliation: Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom.
CNR-Istituto Nazionale di Ottica, Largo E. Fermi 6, I-50125 Firenze, Italy.
INFN, Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino (FI), Italy.
INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, I-38123 Povo, Italy.
College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA.
Abstract: Recent work has unveiled a new class of optical systems that can exhibit the characteristic features of superfluidity. One such system relies on the repulsive photon-photon interaction that is mediated by a thermal
optical nonlinearity and is therefore inherently nonlocal due to thermal diffusion. Here we investigate how such a nonlocal interaction, which at a first inspection would not be expected to lead to superfluid behavior, may be tailored by acting upon the geometry of the photon fluid itself. Our models and measurements show that restricting the laser profile and hence the photon fluid to a strongly elliptical geometry modifies thermal diffusion along the major beam axis and reduces the effective nonlocal interaction length by two orders of magnitude. This in turn enables the system to display a characteristic trait of superfluid flow: the nucleation of quantized vortices in the flow past an extended physical obstacle. These results are general and apply to other nonlocal fluids, such as dipolar Bose-Einstein condensates, and show that “thermal” photon superfluids provide an exciting and novel experimental environment for probing the nature of superfluidity, with applications to the study of quantum turbulence and analog gravity.
Journal/Review: PHYSICAL REVIEW A
Volume: 94 Pages from: 013849-1 to: 013849-9
KeyWords: Quantum fluids of light; Analog gravity models;