Persistent nonlocality in an ultracold-atom environment

TL;DR

This paper explores how nonlocal quantum correlations can be generated and sustained among impurity atoms in an ultracold bosonic environment, revealing robustness against noise and the importance of non-Markovian effects.

Contribution

It demonstrates environment-induced nonlocality in impurity atoms within an ultracold gas, highlighting the role of non-Markovian dynamics in maintaining quantum correlations.

Findings

Impurity atoms exhibit nonlocal states that violate Bell inequalities.

Genuine multipartite nonlocality observed among three impurities.

Non-Markovian effects help preserve nonlocal correlations over time.

Abstract

We investigate nonlocal quantum correlations arising between multiple two-level impurity atoms coupled to an ultracold bosonic gas. We find that the environment-induced dynamics of the impurity subsystem can generate nonlocal states that are robust against noise and violate a multipartite Bell inequality when projective spin measurements are made. Genuine multipartite nonlocality is also observed in a system of three impurities. We show that non-Markovian effects, and the persistence of coherences in the impurity subsystem, are crucial for preventing complete loss of nonlocality and allow for nonlocal correlations to be generated and maintained for extended periods of time.