Violation of an inequality in an experimental test of Leggett's non-local hidden variable theory

TL;DR

This paper reveals that when symmetry conditions are properly included in Leggett's non-local hidden variable theory, the predicted violation of an inequality is much larger than previously reported, challenging the theory's ability to model quantum correlations.

Contribution

The paper introduces symmetry conditions into Leggett's non-local hidden variable theory, leading to a significantly larger predicted violation of an inequality and showing the theory's limitations.

Findings

Maximal violation is 2.5 times larger than previously reported.

Leggett's theory cannot model observed quantum correlations when symmetry conditions apply.

New inequality constrains non-local hidden variable theories.

Abstract

I impose previously neglected symmetry conditions in Leggett's non-local hidden variable theory that are required by the conditions in a recent experimental test of this theory. These conditions lead to an inequality for the polarization correlation function that has a maximal violation from the quantum predictions that is 2.5 times larger than reported in this article. Furthermore, when these symmetry conditions are applicable, Leggett's non-local theory also cannot model the observed quantum correlations in previous experiments.