Highly noise resistant multipartite quantum correlations

Abstract

We analyze robustness of correlations of the $N$-qubit GHZ and Dicke states against white noise admixture. For sufficiently large $N$, the Dicke states (for any number of excitations) lead to more robust violation of local realism than the GHZ states (e.g. for $N=9$ for the W state). We also identify states that are the most resistant to white noise. Surprisingly, it turns out that these states are partially product. As a by-product, we obtain a simple three-setting Bell inequality which is violated by any pure entangled state.