Nonlinear synthetic gauge potentials and sonic horizons in Bose-Einstein condensates

TL;DR

This paper demonstrates how density-dependent synthetic gauge fields in Bose-Einstein condensates can create controllable spacetime geometries, including artificial black holes and cosmological horizons, enabling new experimental simulations of gravitational phenomena.

Contribution

It introduces a novel method linking synthetic gauge fields with spacetime engineering in condensates, allowing control via laser phase rather than flow speed.

Findings

Created artificial black holes in stationary condensates

Simulated charged black holes like Reissner-Nordström

Induced cosmological horizons resembling de Sitter spacetime

Abstract

Phonons in a Bose-Einstein condensate can be made to behave as if they propagate in curved spacetime by controlling the condensate flow speed. Seemingly disconnected to this, artificial gauge potentials can be induced in charge neutral atomic condensates by for instance coupling two atomic levels to a laser field. Here we connect these two worlds and show that synthetic interacting gauge fields, i.e., density-dependent gauge potentials, induce a non-trivial spacetime structure for the phonons. This allows for the creation of new spacetime geometries which depend not on the flow speed of the condensate but on an easily controlled transverse laser phase. Using this, we show how to create artificial black holes in a stationary condensate, we simulate charge in a Reissner-Nordstr\"om black hole and induce cosmological horizons by creating de Sitter spacetimes. We then show how to combine this de Sitter spacetime with a black hole, which also opens up the possibility to study in experiments its quantum stability.