# Superradiant scattering in fluids of light

## TL;DR

This paper provides a theoretical analysis of superradiant scattering in photon fluids, demonstrating how resonant amplification occurs and generalizing previous quantum fluid studies to include quantum pressure effects, with implications for experiments.

## Contribution

It introduces a time-domain approach to analyze superradiance in photon fluids, accounting for quantum pressure, and extends the concept to other systems like atomic Bose-Einstein condensates.

## Key findings

- Resonant amplification reduces to superradiance in the hydrodynamic limit.
- Time-domain formulation captures superradiance as a transient effect.
- Applicability to experimental observation in photon fluids and BECs.

## 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.