Operational Characterization of Multipartite Nonlocal Correlations

TL;DR

This paper refines the operational understanding of multipartite nonlocal correlations, revealing multiple inequivalent types of nonlocality and clarifying previous interpretations within the resource theory framework.

Contribution

It provides a more detailed classification of multipartite no-signaling correlations and clarifies prior results in the operational framework of nonlocality.

Findings

Multiple inequivalent types of multipartite nonlocality identified.

Finer classification of no-signaling correlations established.

Clarification of previous interpretations in the resource framework.

Abstract

Nonlocality, one of the most puzzling features of multipartite quantum correlation, has been identified as a useful resource for device-independent quantum information processing. Motivated by the resource theory of quantum entanglement recently an operational framework have been proposed by Gallego et al. [\href{https://doi.org/10.1103/PhysRevLett.109.070401}{Phys. Rev. Lett. 109, 070401 (2012)}] and Bancal et al. [\href{https://doi.org/10.1103/PhysRevA.88.014102}{Phys. Rev. A 88, 014102 (2013)}] that characterizes the nonlocal resource present in multipartite quantum correlations. While the bipartite no-signaling correlations allows a dichotomous classification -- local vs. nonlocal, in multipartite scenario the authors have shown existence of several types of nonlocality that are inequivalent under the proposed operational framework. In this work we present a finer characterization of multipartite no-signaling correlations based on the same operational framework. We also clarify a statement in Gallego et al.'s work that could be misinterpreted and make the conclusions of that work more precise here.