Entanglement Swapping and Quantum Correlations via Symmetric Joint Measurements
Cen-Xiao Huang, Xiao‐Min Hu, Yu Guo, Chao Zhang, Bi‐Heng Liu, Yun‐Feng Huang, Chuan‐Feng Li, Guang-Can Guo, Nicolas Gisin, Cyril Branciard, Armin Tavakoli
Abstract
We use hyperentanglement to experimentally realize deterministic entanglement swapping based on quantum elegant joint measurements. These are joint projections of two qubits onto highly symmetric, isoentangled bases. We report measurement fidelities no smaller than 97.4%. We showcase the applications of these measurements by using the entanglement swapping procedure to demonstrate quantum correlations in the form of proof-of-principle violations of both bilocal Bell inequalities and more stringent correlation criteria corresponding to full network nonlocality. Our results are a foray into entangled measurements and nonlocality beyond the paradigmatic Bell state measurement and they show the relevance of more general measurements in entanglement swapping scenarios.