Nonclassicality of local bipartite correlations

TL;DR

This paper introduces superlocality as a way to operationally characterize the nonclassicality of local bipartite correlations, highlighting the need for larger shared randomness dimensions to simulate certain quantum correlations.

Contribution

It proposes superlocality as a novel criterion to identify nonclassical correlations in unentangled states within convex operational theories.

Findings

Superlocality indicates nonclassicality in certain local states.

Larger shared randomness dimensions are required to simulate quantum correlations.

Provides a new operational framework for nonclassicality in local correlations.

Abstract

Simulating quantum nonlocality and steering requires augmenting pre-shared randomness with non-vanishing communication cost. This prompts the question of how one may provide such an operational characterization for the quantumness of correlations due even to unentangled states. Here we show that for a certain class of states, such quantumness can be pointed out by superlocality, the requirement for a larger dimension of the pre-shared randomness to simulate the correlations than that of the quantum state that generates them. This provides an approach to define the nonclassicality of local multipartite correlations in convex operational theories.