Facets of Non-locality and Advantage in Entanglement-Assisted Classical Communication Tasks

TL;DR

This paper explores the relationship between non-local correlations and advantages in classical communication tasks, introducing new techniques and demonstrating quantum advantages including qutrit over qubit entanglement.

Contribution

It introduces the wire-cutting and wire-reading techniques, linking Bell inequality violations to communication advantage, and constructs new tasks showing quantum advantage with non-local correlations.

Findings

Bell inequality tailored to correlation-assisted tasks

Quantum correlations can outperform classical strategies

Quantum advantage demonstrated with qutrit over qubit entanglement

Abstract

We reveal key connections between non-locality and advantage in correlation-assisted classical communication. First, using the wire-cutting technique, we provide a Bell inequality tailored to any correlation-assisted bounded classical communication task. The violation of this inequality by a quantum correlation is equivalent to its quantum-assisted advantage in the corresponding communication task. Next, we introduce wire-reading, which leverages the readability of classical messages to demonstrate advantageous assistance of non-local correlations in setups where no such advantage can be otherwise observed. Building on this, we introduce families of classical communication tasks in a Bob-without-input prepare-and-measure scenario, where non-local correlation enhances bounded classical communication while shared randomness assistance yields strictly suboptimal payoff. For the first family of tasks, assistance from any non-local facet leads to optimal payoff, while each task in the second family is tailored to a non-local facet. We reveal quantum advantage in these tasks, including qutrit over qubit entanglement advantage.