Superfluid motion and drag-force cancellation in a fluid of light

Claire Michel,Omar Boughdad,Mathias Albert,Pierre-Élie Larré,Matthieu Bellec

doi:10.1038/s41467-018-04534-9

Abstract

Quantum fluids of light merge many-body physics and nonlinear optics, revealing quantum hydrodynamic features of light when it propagates in nonlinear media. One of the most outstanding evidence of light behaving as an interacting fluid is its ability to carry itself as a superfluid. Here, we report a direct experimental detection of the transition to superfluidity in the flow of a fluid of light past an obstacle in a bulk nonlinear crystal. In this cavityless all-optical system, we extract a direct optical analog of the drag force exerted by the fluid of light and measure the associated displacement of the obstacle. Both quantities drop to zero in the superfluid regime characterized by a suppression of long-range radiation from the obstacle. The experimental capability to shape both the flow and the potential landscape paves the way for simulation of quantum transport in complex systems.

Highlights

Quantum fluids of light merge many-body physics and nonlinear optics, revealing quantum hydrodynamic features of light when it propagates in nonlinear media
Before being theoretically developed for cavity lasers[9,10], the idea of a superfluid motion of light originates from pioneering studies in cavityless all-optical configurations[11] in which the hydrodynamic nucleation of quantized vortices past an obstacle when a laser beam propagates in a bulk nonlinear medium was investigated[12]. In such a cavityless geometry, the paraxial propagation of a monochromatic optical field in a nonlinear medium may be mapped onto a two-dimensional Gross-Pitaevskii-type evolution of a quantum fluid of interacting photons in the plane transverse to the propagation[4]
We reported a direct experimental observation of the transition from a “frictional” to a superfluid regime in a cavityless all-optical propagating geometry

Summary

Introduction

Quantum fluids of light merge many-body physics and nonlinear optics, revealing quantum hydrodynamic features of light when it propagates in nonlinear media. Before being theoretically developed for cavity lasers[9,10], the idea of a superfluid motion of light originates from pioneering studies in cavityless all-optical configurations[11] in which the hydrodynamic nucleation of quantized vortices past an obstacle when a laser beam propagates in a bulk nonlinear medium was investigated[12]. In such a cavityless geometry, the paraxial propagation of a monochromatic optical field in a nonlinear medium may be mapped onto a two-dimensional Gross-Pitaevskii-type evolution of a quantum fluid of interacting photons in the plane transverse to the propagation[4]. In the “frictional”, nonsuperfluid regime, light becomes sensitive to such an index modification and diffracts while hitting it

Methods

Results

Conclusion