Role of geometry in the superfluid flow of nonlocal photon fluids

Vocke, D., Wilson, K., Marino, F., Carusotto, I., Wright, E. M., Roger, T., Anderson, B. P., Öhberg, P. and Faccio, D. (2016) Role of geometry in the superfluid flow of nonlocal photon fluids. Physical Review A: Atomic, Molecular and Optical Physics, 94(1), 013849. (doi: 10.1103/PhysRevA.94.013849)

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.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Faccio, Professor Daniele
• Authors: Vocke, D., Wilson, K., Marino, F., Carusotto, I., Wright, E. M., Roger, T., Anderson, B. P., Öhberg, P., and Faccio, D.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review A: Atomic, Molecular and Optical Physics
• Publisher: American Physical Society
• ISSN: 2469-9926
• ISSN (Online): 2469-9934
• First Published: First published in Physical Review A 94(1):013849
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher