Fig. 5
From: Endurance of quantum coherence due to particle indistinguishability in noisy quantum networks
Experimental two-point (intensity) correlation functions, \(G_{p,q}^{(2)} = \rho _{(p,q),(p,q)}\), for separable a, entangled b, classically correlated c, and incoherent photon pairs d coupled into the upper sites of the waveguide trimer shown in Fig. 1a. The initial states are shown in a–d. The corresponding output correlation patterns, after a propagation distance of z = 12 cm, are shown in e–h. From these experimental results it becomes evident that indistinguishable two-photon states produce similar correlation patterns where photon bunching exhibits the highest probability, while for incoherent distinguishable photons exhibit the highest probability in the antibunching terms
