Phase dependent spectrum of scattered light from two Bose condensates

TL;DR

This paper calculates the spectrum of scattered light from two coupled Bose-Einstein condensates, revealing phase-dependent features that could demonstrate spontaneous gauge symmetry breaking in such systems.

Contribution

It introduces a method to analyze the phase-dependent spectrum of scattered light from coupled Bose condensates, linking optical signals to quantum phase differences.

Findings

Spectrum exhibits phase-dependent features.

Qualitative changes in spectrum relate to condensate phase difference.

Potential to observe spontaneous gauge symmetry breaking.

Abstract

We calculate the spectrum of the scattered light from quantum degenerate atomic gases obeying Bose-Einstein statistics. The atoms are assumed to occupy two ground states which are optically coupled through a common excited state by two low intensity off-resonant light beams. In the presence of a Bose condensate in both ground states, the atoms may exhibit light induced oscillations between the two condensates analogous to the Josephson effect. The spectrum of the scattered light is calculated in the limit of a low oscillation frequency. In the spectrum we are able to observe qualitative features depending on the phase difference between the macroscopic wave functions of the two condensates. Thus, our optical scheme could possibly be used as an experimental realization of the spontaneous breakdown of the U(1) gauge symmetry in the Bose-Einstein condensation.