Proposal for a motional-state Bell inequality test with ultracold atoms

TL;DR

This paper proposes a theoretical experiment to demonstrate Bell inequality violation using momentum-entangled ultracold atoms, employing atom-optics techniques and simulating the process with stochastic methods.

Contribution

It introduces a novel experimental scheme for testing Bell inequalities with ultracold atoms using Bragg pulses and simulates its feasibility with advanced quantum models.

Findings

Predicted Bell parameter S up to 2.5, indicating strong violation.

Demonstrated the feasibility of the scheme with realistic parameters.

Simulated the collision dynamics and interferometry using stochastic Bogoliubov approach.

Abstract

We propose and theoretically simulate an experiment for demonstrating a motional-state Bell inequality violation for pairs of momentum-entangled atoms produced in Bose-Einstein condensate collisions. The proposal is based on realizing an atom-optics analog of the Rarity-Tapster optical scheme: it uses laser-induced Bragg pulses to implement two-particle interferometry on the underlying Bell-state for two pairs of atomic scattering modes with equal but opposite momenta. The collision dynamics and the sequence of Bragg pulses are simulated using the stochastic Bogoliubov approach in the positive-P representation. We predict values of the Clauser-Horne-Shimony-Holt (CHSH) parameter up to S~2.5 for experimentally realistic parameter regimes, showing a strong violation of the CSHS-Bell inequality bounded classically by S<2.