Violation of local realism with freedom of choice

TL;DR

This paper reports an experiment that successfully violates Bell's inequality while closing both the locality and freedom-of-choice loopholes, advancing the understanding of quantum nonlocality under non-deterministic assumptions.

Contribution

It demonstrates a loophole-free violation of Bell's inequality considering stochastic local realism, addressing key experimental challenges in quantum foundations.

Findings

Violates Bell's inequality with loopholes closed

Addresses locality and freedom-of-choice loopholes simultaneously

Supports non-deterministic models of local realism

Abstract

Bell's theorem shows that local realistic theories place strong restrictions on observable correlations between different systems, giving rise to Bell's inequality which can be violated in experiments using entangled quantum states. Bell's theorem is based on the assumptions of realism, locality, and the freedom to choose between measurement settings. In experimental tests, "loopholes" arise which allow observed violations to still be explained by local realistic theories. Violating Bell's inequality while simultaneously closing all such loopholes is one of the most significant still open challenges in fundamental physics today. In this paper, we present an experiment that violates Bell's inequality while simultaneously closing the locality loophole and addressing the freedom-of-choice loophole, also closing the latter within a reasonable set of assumptions. We also explain that the locality and freedom-of-choice loopholes can be closed only within non-determinism, i.e. in the context of stochastic local realism.