Different operational meanings of continuous variable Gaussian entanglement criteria and Bell inequalities

TL;DR

This paper reviews various entanglement criteria for continuous variable Gaussian states, links them to the EPR paradox, and presents experimental measurement of Bell non-locality using a sub-threshold OPO.

Contribution

It provides a unified review of entanglement criteria and introduces an experimental approach to measure Bell non-locality in Gaussian states.

Findings

Link between entanglement criteria and EPR paradox

Expression for Bell non-locality in Gaussian states

Experimental measurement of Bell operator with OPO

Abstract

Entanglement, one of the most intriguing aspects of quantum mechanics, marks itself into different features of quantum states. For this reason different criteria can be used for verifying entanglement. In this paper we review some of the entanglement criteria casted for continuous variable states and link them to peculiar aspects of the original debate on the famous EPR paradox. Moreover, we give a handy expression for valuating Bell-type non-locality on Gaussian states. We also present the experimental measurement of a particular realization of the Bell operator over continuous variable entangled states produced by a sub-threshold type-II OPO.