A Limit on Quantum Nonlocality from an Information Processing Principle

Abstract

Quantum entanglement is known to give rise to nonlocal correlations that are not possible in a classical theory. Even though quantum correlations are stronger than classical correlations, they are still limited by the mathematical structure of quantum mechanics. Since physical limits usually emerge from physical principles, multiple principles were suggested in order to give a more physical explanation of the quantum limit on nonlocal correlations. None of these principles were able to completely rule out all super-quantum correlations. In this work, we study the principle of non-trivial communication complexity (NTCC), that sets a limit on what can be done in a particular information processing setting. Nonlocal correlations that violate this principle are believed to be impossible in nature. In this work, we expand the set of super-quantum correlations that are known to be ruled out by the NTCC principle, thus providing an explanation for their impossibility in quantum mechanics. We achieve this result by studying the consequences of more general super-quantum correlations in a protocol from Brassard, Buhrman, Linden, M ethot, Tapp and Unger. Additionally, we give a new proof of NTCC violation by a certain type of super-quantum correlations studied by Brunner and Skrzypczyk by describing and analyzing a simple and elegant protocol. Our work provides a framework for further studies of the consequences of super-quantum correlations on the NTCC principle.