Proposal for a loophole-free violation of Bell inequalities with a set of single photons and homodyne measurements

TL;DR

This paper proposes a protocol using mesoscopic quantum states of light and homodyne measurements to achieve a large, loophole-free violation of Bell inequalities, with high robustness to losses.

Contribution

It introduces a novel protocol combining mesoscopic quantum states and homodyne measurements for loophole-free Bell tests, enhancing robustness against line losses.

Findings

Efficient generation of mesoscopic quantum states from simple iterative schemes

Demonstration of a protocol for large loophole-free Bell inequality violation

High robustness of the protocol to line losses

Abstract

We demonstrate that different kind of mesoscopic quantum states of light can be efficiently generated from a simple iterative scheme using homodyne heralding. These states exhibit strong non-classical features, and are of great interest for many applications such as quantum error-correcting codes or fundamental testings. On this basis we propose a protocol allowing a large loophole-free violation of a CHSH-type Bell inequality with a remarkable robustness to line losses.