Entropic entanglement criteria in phase space

TL;DR

This paper introduces new entropic criteria for detecting quantum entanglement using the Husimi Q-distribution in phase space, offering practical advantages and success in identifying entanglement in non-Gaussian states where previous methods fail.

Contribution

The authors develop entropic inseparability criteria based on the Husimi Q-distribution, enhancing entanglement detection in non-Gaussian states with practical experimental relevance.

Findings

Criteria detect entanglement in non-Gaussian states where second-order criteria fail

Husimi Q-distribution provides practical advantages for experimental detection

New criteria certify entanglement in previously undetectable regions

Abstract

We derive entropic inseparability criteria for the phase space representation of quantum states. In contrast to criteria involving differential entropies of marginal phase space distributions, our criteria are based on a joint distribution known as the Husimi Q-distribution. This distribution is experimentally accessible in cold atoms, circuit QED architectures and photonic systems and bears practical advantages compared to the detection of marginals. We exemplify the strengths of our entropic approach by considering several classes of non-Gaussian states where second-order criteria fail. We show that our criteria certify entanglement in previously undetectable regions highlighting the strength of using the Husimi Q-distribution for entanglement detection.