Orateur
Description
Superradiance is a universal amplification phenomenon. In the instance of rotational superradiance, amplification occurs when a spatial region of a rotating system supports negative energy waves. Rotational superradiance is thus predicted to occur in compact objects in astrophysics, and may be observed experimentally in vortices in quantum fluids.
In this talk, I will report on our recent observation of rotational superradiance in an experiment with a quantum fluid of light [1,2,3]. I will first present data in configurations where the vortex is dynamically stable (stationary) and then data in which rotational superradiance destabilises the vortex, ie when an ergoregion instability is triggered.
In recent calculations, we predicted that entanglement generated by superradiance could be observed in this system [4], so our ability to trace superradiance from the linear regime of interactions to the nonlinear regime opens the way to investigations of entanglement beyond the non-perturbative regime.
[1] Falque et al, PRL 2025
[2] Guerrero et al, arxiv 2025
[3] Guerrero et al, arxiv 2025
[4] Delhom et al, PRD 2024
