Fig. 3: On-chip characterization and verification of genuine multipartite entanglement in the hypergraph states.
From: Demonstration of hypergraph-state quantum information processing
a Measured quantum state fidelities (Fq) for all the 27 LU-equivalent classes of hypergraph states as well as 2 classes of graph states. Insets: experimentally reconstructed density matrices of three states by the quantum state topographic measurement. Column heights represent the absolute values ∣ρ∣; colors represent the phases \({{{{{{{\rm{Arg}}}}}}}}(\rho )\). The values in parentheses are ± 1σ uncertainty, estimated by Monte Carlo methods considering Poissonian photon statistics. b, c Measured Mermin parameters of μ and \(\tilde{\mu }\). Experimental results confirm the maximum violations of the Mermin–Klyshko type inequalities, indicated by the local hidden variable bound (e.g, blue line in c). Note the error bars for the measured Fq, μ and \(\tilde{\mu }\) are too small to be visible. Dashed lines are theoretical results.
