Critical visibility for N-particle Greenberger-Horne-Zeilinger correlations to violate local realism

TL;DR

This paper derives Bell inequalities for N-particle GHZ states, showing quantum violations grow exponentially with N and that the threshold visibility decreases exponentially, challenging local realism.

Contribution

It introduces new Bell inequalities involving three measurement settings per site for N-particle systems and analyzes their violation by GHZ states.

Findings

Quantum violations grow exponentially with N.

Threshold visibility decreases as (2/3)^N.

Local realism is challenged for high N.

Abstract

A sequence of Bell inequalities for N-particle systems, which involve three settings of each of the local measuring apparatuses, is derived. For Greenberger-Horne-Zeilinger states, quantum mechanics violates these inequalities by factors exponentially growing with N. The threshold visibilities of the multiparticle sinusoidal interference fringes, for which local realistic theories are ruled out, decrease as (2/3)^N.