We discuss an experimentally amenable class of two-particle states of motion giving rise to nonlocal spatial interference under position measurements. Using the concept of modular variables, we derive a separability criterion which is violated by these non-Gaussian states. While we focus on the free motion of material particles, the presented results are valid for any pair of canonically conjugate continuous variable observables and should apply to a variety of bipartite interference phenomena.
@article{arxiv.1103.2779,
title = {Detecting entanglement in spatial interference},
author = {Clemens Gneiting and Klaus Hornberger},
journal= {arXiv preprint arXiv:1103.2779},
year = {2011}
}