Testing Leggett's Inequality Using Aharonov-Casher Effect

TL;DR

This paper proposes a novel method to test Leggett's inequality using the Aharonov-Casher effect with entangled particles, potentially enabling experimental verification of quantum nonlocal realism violations.

Contribution

It introduces a new scheme employing the Aharonov-Casher effect and entangled particles to test Leggett's inequality, with robustness to local inaccuracies.

Findings

Scheme can violate Leggett's inequality under ideal conditions.

Tolerant to local inaccuracies due to topological phase.

Feasible implementation with calcium atomic polarization interferometer.

Abstract

Bell's inequality is established based on local realism. The violation of Bell's inequality by quantum mechanics implies either locality or realism or both are untenable. Leggett's inequality is derived based on nonlocal realism. The violation of Leggett's inequality implies that quantum mechanics is neither local realistic nor nonlocal realistic. The incompatibility of nonlocal realism and quantum mechanics has been urrently confirmed by photon experiments. In our work, we propose to test Leggett's inequality using the Aharonov-Casher effect. In our scheme, four entangled particles emitted from two sources manifest a two-qubit-typed correlation that may result in the violation of the Leggett inequality, while satisfying the no-signaling condition for spacelike separation. Our scheme is tolerant to some local inaccuracies due to the topological nature of the Aharonov-Casher phase. The experimental implementation of our scheme can be possibly realized by a calcium atomic polarization interferometer experiment.