Realization of a sonic black hole analogue in a Bose-Einstein condensate

TL;DR

This paper reports the creation of a sonic black hole analogue in a Bose-Einstein condensate, demonstrating a horizon where sound cannot escape, and analyzing its properties through experiments and simulations.

Contribution

It introduces a novel experimental realization of a sonic black hole in a Bose-Einstein condensate, including the formation of an event horizon and analysis of excitations.

Findings

Successful creation of a sonic event horizon in BEC

Observation of negative energy excitations via Bragg spectroscopy

Flow velocities exceeding the speed of sound by an order of magnitude

Abstract

We have created an analogue of a black hole in a Bose-Einstein condensate. In this sonic black hole, sound waves, rather than light waves, cannot escape the event horizon. A step-like potential accelerates the flow of the condensate to velocities which cross and exceed the speed of sound by an order of magnitude. The Landau critical velocity is therefore surpassed. The point where the flow velocity equals the speed of sound is the sonic event horizon. The effective gravity is determined from the profiles of the velocity and speed of sound. A simulation finds negative energy excitations, by means of Bragg spectroscopy.