Extending Bell inequalities to more parties

TL;DR

This paper introduces a method to extend Bell inequalities to more parties, producing tighter and more powerful inequalities that better detect non-classical correlations in quantum states.

Contribution

The paper presents a novel method for extending Bell inequalities to additional parties and provides conditions for generating tight, more powerful inequalities.

Findings

The method can produce inequalities that are violated more strongly by entangled states.

Extended inequalities can serve as more effective indicators of quantum non-locality.

The approach includes conditions ensuring the tightness of the extended inequalities.

Abstract

We describe a method of extending Bell inequalities from $n$ to $n+1$ parties and formulate sufficient conditions for our method to produce tight inequalities from tight inequalities. The method is non trivial in the sense that the inequalities produced by it, when applied to entangled quantum states may be violated stronger than the original inequalities. In other words, the method is capable of generating inequalities which are more powerfull indicators of non-classical correlations than the original inequalities.