Understanding superradiant phenomena with synthetic vector potentials in atomic Bose-Einstein condensates

Year: 2021

Authors: Giacomelli L.; Carusotto I.

Autors Affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Universita di Trento, via Sommarive 14, Povo, Trento, I-38050, Italy

Abstract: We theoretically investigate superradiance effects in quantum field theories in curved space-times by proposing an analog model based on Bose-Einstein condensates subject to a synthetic vector potential. The breaking of the irrotationality constraint of superfluids allows us to study superradiance in simple planar geometries and obtain intuitive insight into the amplified scattering processes at ergosurfaces. When boundary conditions are modified to allow for reflections, dynamical instabilities are found, similar to the ones of ergoregions in rotating space-times. Their stabilization by horizons in black hole geometries is discussed. All these phenomena are reinterpreted through an exact mapping with the physics of one-dimensional relativistic charged scalar fields in electrostatic potentials. Our study provides a deeper understanding of the basic mechanisms of superradiance: By disentangling the different ingredients at play, it shines light on some misconceptions on the role of dissipation and horizons and on the competition between superradiant scattering and instabilities.


Volume: 103 (4)      Pages from: 043309-1  to: 043309-23

More Information: This work received funding from the European Union Horizon 2020 research and innovation program under Grant Agreement No. 820392 (PhoQuS), the Provincia Autonoma di Trento, and the Q@TNinitiative. Stimulating discussions with Massimiliano Rinaldi, Nicolas Pavloff, Stefano Vitale, and our forever missed friend and master Renaud Parentani are warmly acknowledged.
KeyWords: energy
DOI: 10.1103/PhysRevA.103.043309