Incompatible local hidden-variable models of quantum correlations

TL;DR

This paper demonstrates a quantum state that admits local hidden-variable models for fixed numbers of subsystems but cannot be extended to models covering multiple subsystem counts, highlighting limitations of local realism.

Contribution

It introduces a quantum state with local hidden-variable models for fixed subsystems that cannot be generalized to multiple subsystem configurations, revealing new constraints on local realism.

Findings

Existence of quantum states with fixed-subsystem local models

Inability to extend models to multiple subsystem counts

Highlights limitations of local hidden-variable theories

Abstract

We show a quantum state with explicit local hidden-variable models for correlations between any fixed number of subsystems which cannot be extended to a model simultaneously describing correlations between different numbers of subsystems.