General class of continuous variable entanglement criteria

TL;DR

This paper introduces a versatile and general class of entanglement criteria for continuous variable systems based on the Husimi Q-distribution, capable of detecting entanglement undetected by traditional methods and adaptable to experimental constraints.

Contribution

It develops a unified framework for entanglement detection using concave functions on the Husimi Q-distribution, encompassing existing criteria and enhancing detection capabilities.

Findings

Detects entanglement in states undetected by standard criteria

Provides advantages under finite detector resolution

Unifies various entanglement criteria into a general framework

Abstract

We present a general class of entanglement criteria for continuous variable systems. Our criteria are based on the Husimi $Q$-distribution and allow for optimization over the set of all concave functions rendering them extremely general and versatile. We show that several entropic criteria and second moment criteria are obtained as special cases. Our criteria reveal entanglement of families of states undetected by any commonly used criteria and provide clear advantages under typical experimental constraints such as finite detector resolution and measurement statistics.