Massive phonons and gravitational interactions in photon-fluids

Francesco Marino

Photon-fluids, nonlinear optical systems which can be described in terms of the hydrodynamic equations of an interacting Bose gas, provide a promising platform for fundamental studies of quantum many-body physics. Here we consider a photon-fluid with both local (Kerr) and nonlocal (thermo-optical) interactions. We show that the excitation spectrum consists of massive Bogoliubov modes which, at lower momenta, correspond to massive phonons with a relativistic energy-momentum relation. In the non-relativistic limit, such phonons behave as self-gravitating quantum particles with an effective Schrödinger-Newton dynamics.

Related paper: https://arxiv.org/abs/1908.00875