The interplay of quasi-bound states of black holes and the Hawking effect in a dissipative quantum fluid analogue black hole

Analogue gravity enables the laboratory study of the Hawking effect, the emission of correlated waves on either side of a sonic horizon.

Here, we use a quantum fluid of polaritons as a setup to study the statistics of correlated emission. Polaritons are different from other quantum fluids because their dynamics are driven-dissipative. We show that dissipation may quench zero-norm modes of the system in a manner totally different than in conservative fluids: in polaritons, quantum fluctuations themselves suffice to populate these modes but, instead of growing exponentially, their amplitude decays under dissipation.

Yet, these zero-norm modes manifest themselves as quasi-bound states of the horizon, meaning that they create higher order corrections to the curvature of the effective spacetime in the vicinity of the horizon.

In this context, we study propitious conditions for the Hawking effect and the propagation of correlated waves in the quantum fluid. We numerically compute the spectrum of spatial correlations and find a regime in which the emission is an order of magnitude stronger and longer than in other quantum fluids. We also find that the quasi-bound states mediate the emission by creating a sort of atmosphere from which emission originates on either side of the horizon.

This opens the route for quantitative studies of the influence of dissipation on quantum emission as well as to analogue quantum simulations of black hole spacetimes with higher order corrections to the curvature.