Publication Date

2008

Comments

This is the pre-published version harvested from ArXiv. The published version is located at http://prl.aps.org/abstract/PRL/v101/i15/e155303

Abstract

We analyze the interference pattern produced by ultracold atoms released from an optical lattice, commonly interpreted as the momentum distributions of the trapped quantum gas. We show that for finite times of flight the resulting density distribution can, however, be significantly altered, similar to a near-field diffraction regime in optics. We illustrate our findings with a simple model and realistic quantum Monte Carlo simulations for bosonic atoms and compare the latter to experiments.

Volume

101

Issue

15

Journal Title

Physics Review Letters