Destruction of interference by many-body interactions in cold atomic Bose gases

Abstract

We study the effects of many-body interactions on the interference in a Mach-Zehnder interferometer for matter waves of ultracold Bose atoms. After switching off an axial trapping potential, the thermal initial wavepacket expands, and subsequently interference fringes may be observed in a circular 1D trap. These are computed for axial harmonic or $δ$-function traps, and for interaction strengths from the Thomas-Fermi regime to the Tonks-Girardeau limit. It is shown that many-body correlations in a realistic setup destroy interference to a large degree. Analytical expressions allowing to infer the observability of phase coherence and interference are provided.

7 pages, 4 eps figures, final version, to be published in PRA