Typical local measurements in generalised probabilistic theories: emergence of quantum bipartite correlations

TL;DR

This paper explores how observational limitations in generalized probabilistic theories (GPTs) influence the emergence of quantum correlations, showing that restricted measurements can make GPTs mimic quantum bipartite correlations, while tripartite correlations can surpass quantum limits.

Contribution

It demonstrates that limited local measurements in GPTs can replicate quantum bipartite correlations, using a generalized Dvoretzky's theorem, and highlights the potential for tripartite correlations to exceed quantum bounds.

Findings

Restricted measurements lead to quantum-like bipartite correlations in GPTs

Tripartite correlations in GPTs can surpass quantum correlations

Generalized Dvoretzky's theorem underpins the simulation results

Abstract

What singles out quantum mechanics as the fundamental theory of Nature? Here we study local measurements in generalised probabilistic theories (GPTs) and investigate how observational limitations affect the production of correlations. We find that if only a subset of typical local measurements can be made then all the bipartite correlations produced in a GPT can be simulated to a high degree of accuracy by quantum mechanics. Our result makes use of a generalisation of Dvoretzky's theorem for GPTs. The tripartite correlations can go beyond those exhibited by quantum mechanics, however.