Spontaneous quantum superradiant emission in atomic Bose-Einstein condensates subject to a synthetic vector potential

We theoretically investigate the spontaneous quantum emission of phonon pairs by superradiant processes in an atomic Bose-Einstein condensate subject to a synthetic vector potential. Within the analog gravity perspective, this effect corresponds to the spontaneous emission of radiation from the ergosurface of rotating black holes. A general input-output formalism is built and used to characterize the spectral and correlation properties of the emission. Experimentally accessible signatures of the emission are pointed out in the correlation functions of the atomic gas.