Non-locality and Back-reaction in Acoustic Black Holes and Non-linearity in Quantum Fluid Dynamics
This thesis is mainly about quantum correlations and non-linear fluctuations in quantum fluids. It focuses especially on collective quantum fluctuations, i.e. sound waves, in the stationary flow of a 1D Bose-Einstein quasi- condensate which exhibits an acoustic horizon, i.e. a transition from subsonic to supersonic flow. Quantum phenomena generated by the presence of the horizon are investigated. The thesis also presents a brief excursus on two- dimensional turbulence in a quantum fluid. We study quantum non-separability, non- locality and back-reaction of the acoustic Hawking radiation emitted by an analog black hole. The entanglement and nonlocal correlations within the tripartite system of quasi-particles emitted from the acoustic horizon are first investigated. Back-reaction equations govern- ing the effect of such acoustic radiation on the inhomogeneous background are derived and stationary solutions are considered. Finally, a phenomenological theory based on topological constraints for vortex creation and annihilation is effectively applied to experimental data, thus accounting for the growth and decay of turbulence.
Jury : Jacqueline Bloch, Andreas Buchleitner (co-directeur de thèse), Marek Kus, Nicolas Pavloff (directeur de thèse), Heidi Rzehak, Augusto Smerzi