Nonlocality from N>2 independent single-photon 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 1/√2≈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.