All Entangled Quantum States Are Nonlocal

TL;DR

This paper demonstrates that all entangled quantum states exhibit nonlocality by using nonlocal games, providing necessary and sufficient conditions for state transformation via local operations and shared randomness.

Contribution

It introduces a new framework linking state interconversion to nonlocal game payoffs, revealing nonlocality in all entangled states.

Findings

Nonlocal games can witness entanglement in any quantum state.

Necessary and sufficient conditions for state transformation are established.

All entangled states are shown to be nonlocal through this framework.

Abstract

Departing from the usual paradigm of local operations and classical communication adopted in entanglement theory, here we study the interconversion of quantum states by means of local operations and shared randomness. A set of necessary and sufficient conditions for the existence of such a transformation between two given quantum states is given in terms of the payoff they yield in a suitable class of nonlocal games. It is shown that, as a consequence of our result, such a class of nonlocal games is able to witness quantum entanglement, however weak, and reveal nonlocality in any entangled quantum state. An example illustrating this fact is provided.