Almost all pure entangled states enable unbounded nonlocality sharing

Abstract:We establish a connection between Hardy's paradox and nonlocality sharing in sequential bipartite scenarios, where each subsystem is measured in turn by a chain of observers. We show that any correlations exhibiting a Hardy paradox in the two-input two-output scenario enable sequential violations of the CHSH inequality between arbitrarily many pairs of observers, using only projective measurements and the assistance of a small local ancilla system. Since almost all pure entangled states, with the only exception of the maximally entangled one, admit Hardy correlations, our protocol applies generically: almost all pure entangled states, if assisted by a local ancilla, allow for nonlocality sharing between arbitrarily many observer pairs using only projective measurements.

arXiv:2607.24700 [quant-ph]

(or arXiv:2607.24700v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2607.24700 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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