Detection and engineering of spatial mode entanglement with ultra-cold bosons

TL;DR

This paper proposes an interferometric method to detect and manipulate spatial entanglement in ultra-cold Bose gases, revealing how entanglement varies with temperature and interactions.

Contribution

It introduces a novel interferometric scheme for detecting multi-mode spatial entanglement in finite-temperature Bose gases with fixed particle number.

Findings

Entanglement decreases rapidly with temperature but persists at zero temperature.

Interaction tuning can modify the distribution of entanglement among spatial modes.

Significant entanglement remains at zero temperature regardless of interaction strength.

Abstract

We outline an interferometric scheme for the detection of bi-mode and multi-mode spatial entanglement of finite-temperature,interacting Bose gases of fixed particle number. Whether entanglement is present in the gas depends on the existence of the single-particle reduced density matrix between different regions of space. We apply the scheme to the problem of a harmonically trapped boson pair and show that while entanglement is rapidly decreasing with temperature, a significant amount remains for all interaction strengths at zero temperature.Thus, by tuning the interaction parameter, the distribution of entanglement between many spatial modes can be modified.