Spin squeezing and EPR entanglement of two bimodal condensates in state-dependent potentials

TL;DR

This paper proposes a scheme to generate and analyze EPR entanglement and spin-squeezing between two spatially separated bimodal Bose-Einstein condensates using state-dependent potentials, with potential implementation on atom chips.

Contribution

It introduces a method to create and analyze non-local quantum correlations and EPR entanglement in bimodal condensates via elastic collisions in a state-dependent potential.

Findings

EPR entanglement is generated at short times.

Spin-squeezing occurs in each condensate.

Macroscopic entangled states form at long times.

Abstract

We propose and analyze a scheme to entangle the collective spin states of two spatially separated bimodal Bose-Einstein condensates. Using a four-mode approximation for the atomic field, we show that elastic collisions in a state-dependent potential simultaneously create spin-squeezing in each condensate and entangle the collective spins of the two condensates. We investigate mostly analytically the non-local quantum correlations that arise in this system at short times and show that Einstein-Podolsky-Rosen (EPR) entanglement is generated between the condensates. At long times we point out macroscopic entangled states and explain their structure. The scheme can be implemented with condensates in state-dependent microwave potentials on an atom chip.