EurekAlert  August 12, 2024 Although progress has been reported in the generation of mutually entangled multi-photon quantum light states using free space apparatus, high-fidelity high-rate on-chip entanglement generation is important for future scalability. An international team of researchers (France, Italy, Brazil) used a bright quantum-dot based single-photon source to demonstrate the high-fidelity generation of 4-photon Greenberg-Horne-Zeilinger (GHZ) states with a low-loss reconfigurable glass photonic circuit. They reconstructed the density matrix of the generated states using full quantum-state tomography reaching an experimental fidelity and purity. The entanglement of the generated states was certified with a semi device-independent approach through the violation […]