Bosonic bunching reveals strong contextual behaviour

TL;DR

This paper demonstrates that bosonic bunching can lead to violations of certain quantum inequalities beyond known bounds, revealing strong contextual behavior in quantum systems.

Contribution

It introduces a novel approach showing that bosonic systems with bunching effects can violate inequalities under less restrictive conditions than previously assumed.

Findings

Violation of Klyachko-Can-Binicioglu-Shumovsky inequality exceeds √5

Existence of three pairwise exclusive events with combined probability 3/2

Bosonic bunching reveals strong contextuality in quantum systems

Abstract

We show that violation of Klyachko-Can-Binicioglu-Shumovsky [Phys. Rev. Lett. {\bf 101}, 020403 (2008)] pentagram-like inequality can exceed $\sqrt{5}$ provided that exclusive events do not have to be comeasurable and that one uses bosonic systems which exhibit bunching effects. We also show that in this case one can find three pairwise exclusive events whose sum of probabilities is 3/2.