Non-locality from N > 2 Independent Single Photon Emitters

TL;DR

This paper shows that multiple independent single-photon emitters can produce intensity correlations that violate locality, revealing a form of entanglement created during detection, even with low visibility signals.

Contribution

The authors derive a new Bell-Wigner-type inequality applicable to various setups and demonstrate its violation with N > 2 emitters, highlighting a novel form of path entanglement.

Findings

Violations occur with visibility below 71%

Path entanglement is generated during detection

Intensity correlations can violate locality with multiple emitters

Abstract

We demonstrate that intensity correlations of second order in the fluorescence light of N > 2 single- photon emitters may violate locality while the visibility of the signal remains below 71%. For this, we derive a homogeneous Bell-Wigner-type inequality, which can be applied to a broad class of experimental setups. We trace the violation of this inequality back to path entanglement created by the process of detection.