An interplay between nonlocality and quantum violation of path-spin noncontextuality

TL;DR

This paper explores how the violation of a noncontextual realist inequality in single-particle path-spin entanglement reveals a form of nonlocality distinct from traditional Bell nonlocality, impacting hidden variable theories.

Contribution

It demonstrates a novel connection between nonlocality and quantum violation of noncontextuality in single-particle systems, expanding understanding beyond interparticle entanglement.

Findings

Violation of a Bell-type path-spin noncontextual inequality observed in neutrons.

Identifies a form of nonlocality necessary for hidden variable models to align with quantum mechanics.

Highlights the interplay between nonlocality and noncontextuality in quantum systems.

Abstract

In terms of a suitable variant of the EPR-Bohm example, we argue that the quantum mechanically predicted and experimentally verified violation of a Bell-type path-spin noncontextual realist inequality for an `intraparticle' path-spin entanglement involving single neutrons can be used to infer a form of nonlocality, distinct from Bell-type nonlocality, that is required for any relevant hidden variable model to be compatible with the quantum mechanical treatment of an EPR-Bohm-type `interparticle' entanglement.