Coherence properties of an atom laser

TL;DR

This paper investigates the coherence properties of an atom laser derived from a Bose-Einstein condensate, analyzing experimental data through numerical and analytical models to understand phase effects on coherence length.

Contribution

It provides a detailed analysis of atom laser coherence using 3D Gross-Pitaevskii simulations and a Thomas-Fermi model, matching experimental results.

Findings

Coherence length is significantly influenced by the condensate's phase evolution.

Good agreement between simulations and experimental data.

Phase development impacts coherence when trapping potential is removed.

Abstract

We study the coherence properties of an atom laser, which operates by extracting atoms from a gaseous Bose-Einstein condensate via a two-photon Raman process, by analyzing a recent experiment. We obtain good agreement with the experimental data by solving the time-dependent Gross-Pitaevskii equation in three dimensions both numerically and with a Thomas-Fermi model. The coherence length is strongly affected by the space-dependent phase developed by the condensate when the trapping potential is turned off.