Detecting entanglement in spatial interference

TL;DR

This paper introduces a new method for detecting entanglement in two-particle spatial interference using modular variables, applicable to non-Gaussian states and various bipartite systems.

Contribution

It develops a separability criterion based on modular variables for non-Gaussian states, enhancing entanglement detection in spatial interference experiments.

Findings

The criterion is violated by certain non-Gaussian states exhibiting nonlocal interference.

Results are applicable to any pair of conjugate continuous variables.

The approach is experimentally feasible for free particles.

Abstract

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.