Superradiant scattering in fluids of light

Abstract

We theoretically investigate the scattering process of Bogoliubov excitations on a rotating photon-fluid. Using the language of Noether currents we demonstrate the occurrence of a resonant amplification phenomenon, which reduces to the standard superradiance in the hydrodynamic limit. We make use of a time-domain formulation where superradiance emerges as a transient effect encoded in the amplitudes and phases of propagating localised wavepackets. Our findings generalize previous studies in quantum fluids to the case of a non-negligible quantum pressure and can be readily applied also to other physical systems, in particular atomic Bose-Einstein condensates. Finally we discuss ongoing experiments to observe superradiance in photon fluids, and how our time domain analysis can be used to characterise superradiant scattering in non-ideal experimental conditions.

11 pages, 6 figures Version 2: Updated first author affiliation, fixed grammatical typos

References in corpus (4)

• Measurement of stimulated Hawking emission in an analogue system
• Acoustic black holes in a two-dimensional "photon-fluid"
• Quasi-normal frequencies: Key analytic results
• Nonlinear Zel'dovich effect: Parametric amplification from medium rotation

Cited by in corpus (1)

• Analogy between freezing lakes and the cosmic radiation era