Zel'dovich-Starobinsky Effect in Atomic Bose-Einstein Condensates: Analogy to Kerr Black Hole

TL;DR

This paper explores the analogy between the Zel'dovich-Starobinsky effect in atomic Bose-Einstein condensates and Kerr black holes, demonstrating quantum radiation phenomena via effective acoustic metrics and ergosurfaces.

Contribution

It introduces the concept of quantum radiation from a moving object in BECs analogous to black hole radiation, highlighting the role of ergosurfaces in quasiparticle creation.

Findings

Radiation occurs even below Landau critical velocity.

Quasiparticle creation is linked to the ergosurface within the condensate.

Radiation rate depends on the ergosurface's position.

Abstract

We consider circular motion of a heavy object in an atomic Bose-Einstein condensate (BEC) at $T=0{\rm K}$. Even if the linear velocity of the object is smaller than the Landau critical velocity, the object may radiate quasiparticles and thus experience the quantum friction. The radiation process is similar to Zel'dovich-Starobinskii (ZS) effect -- the radiation by a rotating black hole. This analogy emerges when one introduces the effective acoustic metric for quasiparticles. In the rotating frame this metric has an ergosurface, which is similar to the ergosurface in the metric of a rotating black hole. In a finite size BEC, the quasiparticle creation takes place when the ergosurface is within the condensate and occurs via quantum tunneling from the object into the ergoregion. The dependence of the radiation rate on the position of the ergosurface is investigated.