An atomic Hong-Ou-Mandel experiment

TL;DR

This paper demonstrates an atomic analog of the Hong-Ou-Mandel effect, showing two-atom interference, which could enable tests of quantum mechanics with massive particles and advance quantum information applications.

Contribution

It presents the first realization of a Hong-Ou-Mandel experiment with atoms, extending quantum interference studies to massive particles.

Findings

Successful demonstration of atom-based two-particle interference.

Potential for testing Bell's inequalities with massive particles.

New methods for generating and benchmarking twin-atom pairs.

Abstract

The celebrated Hong, Ou and Mandel (HOM) effect is one of the simplest illustrations of two-particle interference, and is unique to the quantum realm. In the original experiment, two photons arriving simultaneously in the input channels of a beam-splitter were observed to always emerge together in one of the output channels. Here, we report on the realisation of a closely analogous experiment with atoms instead of photons. This opens the prospect of testing Bell's inequalities involving mechanical observables of massive particles, such as momentum, using methods inspired by quantum optics, with an eye on theories of the quantum-to-classical transition. Our work also demonstrates a new way to produce and benchmark twin-atom pairs that may be of interest for quantum information processing and quantum simulation.