Event horizons and ergoregions in 3He

Abstract

Event horizons for fermion quasiparticles naturally arise in moving textures in superconductors and Fermi superfluids. We discuss the example of a planar soliton moving in a superfluid 3He−A, which is closely analogous to a charged rotating black hole. The moving soliton will radiate quasiparticles via the Hawking effect at a temperature of about 5 μK, and via vacuum polarization induced by the effective “electromagnetic field” and “ergoregion.” The superfluid 3He−A thus appears to be a useful system for experimental and theoretical simulations of quantum effects related to event horizons and ergoregions.