Interferometric Unruh detectors for Bose-Einstein condensates

TL;DR

This paper proposes an interferometric method to observe an analogue of the circular Unruh effect using a laser coupled to a Bose-Einstein condensate, making the effect experimentally accessible.

Contribution

It introduces a novel interferometric scheme to simulate and detect the Unruh effect in a BEC-based analogue system.

Findings

The effective speed of light is reduced by 12 orders of magnitude in the BEC.

Detectors moving near the sound speed can observe the Unruh effect.

The laser acts as an effective Unruh-DeWitt detector in the system.

Abstract

The Unruh effect predicts a thermal response for an accelerated detector moving through the vacuum. Here we propose an interferometric scheme to observe an analogue of the circular Unruh effect using a localized laser coupled to a Bose-Einstein condensate (BEC). Quantum fluctuations in the condensate are governed by an effective relativistic field theory, and as demonstrated, the coupled laser field acts as an effective Unruh-DeWitt detector thereof. The effective speed of light is lowered by 12 orders of magnitude to the sound velocity in the BEC. For detectors traveling close to the sound speed, observation of the Unruh effect in the analogue system becomes experimentally feasible.