Analog hawking radiation from acoustic black holes
This research activity aims at the development of optical and/or condensed matters analog models of gravitational black holes and, in particular, at the study of the so-called Hawking emission from the horizon. Such analog models are characterized by having some excitation mode whose spatio-temporal evolution is described by a quantum field theory on a curved space-time:in quantum gases of ultracold atoms or of photons, it can be a low-energy phonon mode. In optical systems, it can be some -typically dispersive- photonic mode. At a black hole horizon, quantum fluctuations of the field are converted into pairs of entangled quanta that propagates in opposite directions, forming the celebrated Hawking radiation.
Starting from 2006, the Trento group is active in the theoretical study of the main conceptual features of analog models in close collaboration with colleagues at the Bologna, Pavia, Paris-Sud universities (fig.1). Presently, we are investigating how the entanglement between the Hawking partners can be experimentally revealed and how it survives the intrinsic dissipation of optical systems.
In addition to the purely theoretical work, the Trento group is involved in collaborations with several experimental groups. As a most remarkable recent result, the first experimental realization of a black hole horizon in a quantum fluid of light has been recently reported at LPN (Marcoussis, France) following a Trento-Pavia proposal (fig. 2); starting from 2015, this collaboration is supported by the AQuSproject financed by the EUin the FET-Proactive program. Another collaboration with Heriot-Watt University in Edinburgh is investigating the potential of quantum fluids of light in a cavity-less, propagating geometry to study analog black holes in the absence of losses.
Theoretical prediction of the Hawking radiation signal in the density-density correlation function of a flowing atomic condensate
Sketch of the experimental device used to generate an acoustic black hole in a flowing fluid of light