Three-observable measurement of the critical velocity in a paraxial superfluid of light flowing past a mobile impurity
Year: 2026
Type: preprint
Abstract: We report the measurement of the critical velocity of a paraxial superfluid of light flowing past a mobile impurity, realized using a dual-wavelength optical scheme in a warm vapor of $^{87}\text{Rb}$. The superflow is two-dimensional by nature, while the impurity features a highly repulsive potential, a large tunable radius, and a finite mass. The critical velocity is evaluated by simultaneously monitoring three complementary observables: the number of vortices nucleated in the wake of the impurity, the hydrodynamic force exerted on it, and its displacement velocity relative to the flow. These independent methods yield consistent values for the critical velocity, which remain systematically below the Landau criterion and decrease with the impurity radius, in qualitative agreement with theoretical expectations. Our results demonstrate the reliability of these combined diagnostics, establishing paraxial superfluids of light as a versatile platform for exploring the impurity problem in quantum hydrodynamics.
Source: arXiv (Cornell University)
Institutions: Centre National de la Recherche Scientifique, Collège de France, Université Paris Sciences et Lettres, Laboratoire Kastler Brossel, École Normale Supérieure - PSL, Sorbonne Université, European Laboratory for Non-Linear Spectroscopy, University of Florence, Universidade do Porto, INESC TEC, Université Côte d'Azur, Institut de Physique de Nice, Université Paris-Saclay, Laboratoire de Physique Théorique et Modèles Statistiques
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: Uni-dimensional Quantum dynamics in Ring trapS, Fluids of light in hollow-core fiber micro-cells, Quantum Simulators for One-dimensional systems with PHotons and Atoms, One-dimnesional out-of-equilibriumm quantum dynamics, Nuclear Quantum Entangled States Sensors, Superfluid and turbulent light in complex media, G7080048889
OpenAlex ID: W7208752055