Hawking radiation on an ion ring in the quantum regime

This paper discusses a recent proposal for the simulation of acoustic black holes with ions (Horstmann et al 2010 Phys. Rev. Lett. 104 250403). Ions are rotating on a ring with an inhomogeneous but stationary velocity profile. Phonons cannot leave a region in which the ion velocity exceeds the group velocity of the phonons, because light cannot escape from a black hole. The system is described by a discrete field theory with a nonlinear dispersion relation. Hawking radiation is emitted by this acoustic black hole, generating entanglement between the inside and the outside of the black hole. We study schemes for detecting the Hawking effect in this setup.