Diffraction of entangled particles by light gratings

TL;DR

This paper investigates how entangled particles diffract through light gratings, revealing interference patterns and the influence of entanglement on diffraction, exchange effects, and the structure of non-separable states.

Contribution

It provides a detailed analysis of the diffraction of momentum-entangled particles, highlighting the role of entanglement in diffraction patterns and exchange effects, including new insights into multi-mode Gaussian states.

Findings

Detection patterns show two-particle interferences.

Discontinuity in joint detection probabilities linked to non-separable states.

Entanglement can cancel exchange effects in identical particles.

Abstract

We analyze the diffraction regime of the Kapitza-Dirac effect for particles entangled in momentum. The detection patterns show two-particle interferences. In the single-mode case we identify a discontinuity in the set of joint detection probabilities, associated with the disconnected character of the space of non-separable states. For Gaussian multi-mode states we derive the diffraction patterns, providing an example of the dependence of the light-matter interaction on entanglement. When the particles are identical, we can explore the relation between exchange and entanglement effects. We find a complementary behavior between overlapping and Schmidt's number. In particular, symmetric entanglement can cancel the exchange effects.