The effect of light assisted collisions on matter wave coherence in superradiant Bose-Einstein condensates

TL;DR

This paper experimentally studies how light assisted collisions affect matter wave coherence in Bose-Einstein condensates, revealing asymmetries and higher coherence loss rates near resonance, and proposes a model to explain these effects.

Contribution

It provides the first detailed experimental analysis of light assisted collision effects on matter wave coherence in BECs and introduces a simplified model to interpret the results.

Findings

Asymmetry in coherence loss between blue and red detuned light

Higher coherence loss rates for blue detuned light than previously estimated

A new experimental approach to study strongly coupled light-matter systems

Abstract

We investigate experimentally the effects of light assisted collisions on the coherence between momentum states in Bose-Einstein condensates. The onset of superradiant Rayleigh scattering serves as a sensitive monitor for matter wave coherence. A subtle interplay of binary and collective effects leads to a profound asymmetry between the two sides of the atomic resonance and provides far bigger coherence loss rates for a condensate bathed in blue detuned light than previously estimated. We present a simplified quantitative model containing the essential physics to explain our experimental data and point at a new experimental route to study strongly coupled light matter systems.