Testing a Bell inequality in multi-pair scenarios

TL;DR

This paper demonstrates how to violate the CHSH inequality in multi-pair quantum systems without addressing individual particles, providing insights into the relationship between entanglement and nonlocality.

Contribution

It introduces a method to test Bell inequalities in multi-pair scenarios without individual particle access, analyzing noise, losses, and particle distinguishability.

Findings

Violation of CHSH inequality in multi-pair systems demonstrated

Analysis of noise and loss effects on nonlocality tests

Comparison between distinguishable and indistinguishable particles

Abstract

To date, most efforts to demonstrate quantum nonlocality have concentrated on systems of two (or very few) particles. It is however difficult in many experiments to address individual particles, making it hard to highlight the presence of nonlocality. We show how a natural setup with no access to individual particles allows one to violate the CHSH inequality with many pairs, including in our analysis effects of noise and losses. We discuss the case of distinguishable and indistinguishable particles. Finally, a comparison of these two situations provides new insight into the complex relation between entanglement and nonlocality.