Entangling the free motion of a particle pair: an experimental scenario

TL;DR

This paper proposes an experimental setup using Feshbach dissociation of a molecular Bose-Einstein condensate to generate entangled atomic pairs, enabling Bell inequality tests through position measurements.

Contribution

It details a novel experimental scheme for creating and detecting motional entanglement in atom pairs via dissociation and magnetic pulse sequences.

Findings

The setup can produce entangled atom pairs separated by macroscopic distances.

The proposed experiment is capable of violating a Bell inequality.

Using realistic parameters, the scheme is feasible with current technology.

Abstract

The concept of dissociation-time entanglement provides a means of manifesting non-classical correlations in the motional state of two counter-propagating atoms. In this article, we discuss in detail the requirements for a specific experimental implementation, which is based on the Feshbach dissociation of a molecular Bose-Einstein condensate of fermionic lithium. A sequence of two magnetic field pulses serves to delocalize both of the dissociation products into a superposition of consecutive wave packets, which are separated by a macroscopic distance. This allows to address them separately in a switched Mach-Zehnder configuration, permitting to conduct a Bell experiment with simple position measurements. We analyze the expected form of the two-particle wave function in a concrete experimental setup that uses lasers as atom guides. Assuming viable experimental parameters the setup is shown to be capable of violating a Bell inequality.