English

The Richness of Bell Nonlocality: Generalized Bell Polygamy and Hyper-Polygamy

Quantum Physics 2026-05-13 v2

Abstract

Non-classical quantum correlations underpin both the foundations of quantum mechanics and modern quantum technologies. Among them, Bell nonlocality is a central example. For bipartite Bell inequalities, nonlocal correlations obey strict monogamy: a violation of one inequality precludes violations of other inequalities on the overlapping subsystems. In the multipartite setting, however, Bell nonlocality becomes inherently polygamous. This was previously shown for subsystems obtained by removing a single particle from an NN-partite system. Here, we generalize this result to arbitrary (Nk)(N-k)-partite subsystems. We demonstrate that a single NN-qubit state can violate all (Nk)\binom{N}{k} relevant Bell inequalities simultaneously. We further construct an NN-qubit Bell inequality, obtained by symmetrizing the (Nk)(N-k)-qubit ones, that is maximally violated by states exhibiting this generalized polygamy. We compare these violations with those achievable by GHZ states and show that polygamy offers an advantage in multipartite scenarios, providing new insights into scalable certification of non-classicality in quantum devices. Our analysis relies on symmetry properties of the MABK inequalities. Finally, we show that this behavior can occur across multiple subsystem sizes, a phenomenon we call hyper-polygamy. These structures reveal the remarkable abundance of nonlocality present in multipartite quantum states and offer perspectives for their applications in quantum technologies.

Keywords

Cite

@article{arxiv.2512.09034,
  title  = {The Richness of Bell Nonlocality: Generalized Bell Polygamy and Hyper-Polygamy},
  author = {Gerard Anglès Munné and Paweł Cieśliński and Jan Wójcik and Wiesław Laskowski},
  journal= {arXiv preprint arXiv:2512.09034},
  year   = {2026}
}

Comments

8 pages, 1 figure, few comments added