Quantum Mechanical description of Bell's experiment assumes Locality

TL;DR

The paper demonstrates that the standard quantum mechanical description of Bell's experiment inherently assumes locality, challenging the necessity of non-local effects within quantum theory and impacting quantum information security.

Contribution

It shows that Bell's experiment, when described via von Neumann measurement theory, explicitly assumes locality, contrasting with classical hidden variable theories that require non-locality.

Findings

Quantum mechanics inherently assumes locality in Bell's experiment.

Non-locality is unnecessary within quantum mechanics to explain Bell's experiment.

Implications for quantum randomness and quantum key distribution security.

Abstract

Here it is shown that the simplest description of Bell's experiment according to the canon of von Neumann's theory of measurement explicitly assumes the (Quantum Mechanics-language equivalent of the classical) condition of Locality. This result is complementary to a recently published one demonstrating that non-Locality is necessary to describe said experiment within the framework of classical hidden variables theories, but that it is unnecessary to describe it within the framework of Quantum Mechanics. Summing up these and other related results, it is concluded that, within the framework of Quantum Mechanics, there is absolutely no reason to believe in the existence of non-Local effects. In addition to its foundational significance, this conclusion has practical impact in the fields of quantum-certified and device-independent randomness generation and on the security of Quantum Key Distribution schemes using entangled states.