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

TL;DR

This paper investigates how many-body interactions in ultracold Bose gases affect interference patterns in a Mach-Zehnder interferometer, showing that correlations can significantly suppress observable interference.

Contribution

It provides analytical expressions and numerical analysis demonstrating the destructive impact of many-body correlations on interference in cold atomic Bose gases.

Findings

Many-body correlations destroy interference fringes in realistic setups.

Interference observability depends on interaction strength and trap configuration.

Analytical formulas help predict phase coherence in experiments.

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 $\delta$-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.