Non-Locality distillation in tripartite NLBs

TL;DR

This paper explores protocols to enhance non-local correlations in tripartite non-local boxes, specifically GHZ and certain classes, by distilling weaker non-local systems into stronger correlations, advancing quantum information theory.

Contribution

It introduces non-locality distillation protocols tailored for tripartite NLBs, including GHZ and specific no-signalling classes, a novel extension in the field.

Findings

Protocols successfully increase non-local correlations in tripartite NLBs.

Distillation improves the strength of non-locality in GHZ and class 44,45,46 boxes.

Results demonstrate potential for enhanced quantum communication applications.

Abstract

In quantum mechanics some spatially separated sub-systems behave as if they are part of a single system, the superposition of states of this single system cannot be written as products of states of individual sub-systems,we say that the state of such system is entangled, such systems give rise to non-local correlations between outcomes of measurements. The non-local correlations are conditional probability distributions of some measurement outcomes given some measurement settings and cannot be explained by shared information.These correlations can be studied using a non-local box(NLB) which can be viewed as a quantum systema. A NLB is an abstract object which has number of inputs(measurement settings) and number of outputs(outcomes), such NLBs can be both quantum and super-quantum. The correlations are of use in quantum information theory, the stronger the correlations the more useful they are, hence we study protocols that have multiple weaker non-local systems, application of these protocols to weaker systems may result in stronger non-local correlations, we call such protocols non-locality distillation protocols. In our work here we present non-locality distillation protocols for tripartite NLBs specifically GHZ box and class 44,45 and 46 of no-signalling polytope.