2017/06/16 by Juan Yin, Yuan Cao, Yu-Huai Li +31 · 12 citations
Computer Science · Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Quantum Information and Cryptography #Quantum Mechanics and Applications
paper · doi:10.1126/science.aan3211
openalex publication_date 2017/06/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
Long-distance entanglement distribution is essential for both foundational tests of quantum physics and scalable quantum networks. Owing to channel loss, however, the previously achieved distance was limited to ~100 kilometers. Here we demonstrate satellite-based distribution of entangled photon pairs to two locations separated by 1203 kilometers on Earth, through two satellite-to-ground downlinks with a summed length varying from 1600 to 2400 kilometers. We observed a survival of two-photon entanglement and a violation of Bell inequality by 2.37 ± 0.09 under strict Einstein locality conditions. The obtained effective link efficiency is orders of magnitude higher than that of the direct bidirectional transmission of the two photons through telecommunication fibers.