Observation of nonlocality sharing via not-so-weak measurements

TL;DR

This paper demonstrates experimentally that nonlocality in quantum entanglement can be shared among multiple observers using near-maximum strength weak measurements, advancing understanding of quantum measurement effects.

Contribution

It introduces an optimal protocol for nonlocality sharing among three observers and shows experimental validation with strong measurements, expanding previous weak measurement approaches.

Findings

Nonlocality can be shared with near-maximum strength measurements.

Experimental validation of nonlocality sharing among three observers.

Implications for quantum steering and communication networks.

Abstract

Nonlocality plays a fundamental role in quantum information science. Recently, it has been theoretically predicted and experimentally demonstrated that the nonlocality of an entangled pair may be shared among multiple observers using weak measurements with moderate strength. Here we devise an optimal protocol of nonlocality sharing among three observers and show experimentally that nonlocality sharing may be also achieved using weak measurements with near-maximum strength. Our result sheds light on the interplay between nonlocality and quantum measurements and, may find applications in quantum steering, unbounded randomness certification and quantum communication network.