Bell non-locality in two-mode Gaussian states revealed via local squeezing

TL;DR

This paper demonstrates that local squeezing operations can reveal Bell non-locality in two-mode Gaussian states, enabling the violation of Bell inequalities through local transformations and measurements.

Contribution

It introduces an extended family of observables using local squeezing to detect non-locality in Gaussian states, which was not previously possible with standard methods.

Findings

Local squeezing enables Bell inequality violations in Gaussian states.

Non-locality can be revealed in pure and mixed states using local squeezing and photon detection.

The method broadens the class of Gaussian states where non-locality can be experimentally observed.

Abstract

Local unitary transforms cannot affect the quantum correlations between two systems sharing an entangled state although they do influence the outcomes of local measurements. By considering local squeezing operations we introduce an extended family of observables allowing violation of the CHSH Bell inequality for two-mode Gaussian systems. We show that local squeezing can enable or enhance the identification of non-local two-mode states. In particular, we show that local squeezing followed by photons/no-photons discrimination can suffice to reveal non-locality in a broad ensemble of pure and mixed two-mode Gaussian states.