Field Test of Twin-Field Quantum Key Distribution through Sending-or-Not-Sending over 428 km

Quantum key distribution endows people with information-theoretical security in communications. Twin-field quantum (TF-QKD) has attracted considerable attention because of its outstanding rates over long distances. Recently, several demonstrations TF-QKD have been realized. Nevertheless, those experiments are implemented the laboratory, and therefore a critical question remains about whether is feasible real-world circumstances. Here, by adopting sending-or-not-sending twin-field QKD (SNS-TF-QKD) method actively odd parity pairing (AOPP), we demonstrate field-test 428 km deployed commercial fiber two users physically separated 300 straight line. To this end, explicitly measure relevant properties develop carefully designed system high stability. The secure rate achieved breaks absolute limit repeaterless QKD. result provides new distance record for field test both all types fiber-based systems. Our work bridges gap between laboratory practical applications paves way an intercity network measurement-device-independent security.Received 12 January 2021Accepted 10 May 2021DOI:https://doi.org/10.1103/PhysRevLett.126.250502© 2021 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasOptical information processingQuantum cryptographyQuantum opticsQuantum InformationAtomic, Molecular & Optical