Chinese Scientists Have Set A New Record Of 509 Kilometers Of Fiber-optic Quantum Communication

- Mar 04, 2020-

On March 3, daily reporter learns from jinan quantum technology research institute of science and technology, the first experiment to verify the feasibility of double a quantum key distribution, over a long distance 300 kilometers achieved in the real environment of fiber in double quantum key distribution after the experiment, a researcher with the institute professor xiangbin wang, liu jinan quantum technologies and academician of the Chinese university of science and technology jian-wei pan team cooperation again, 509 kilometers achieved real environment fiber double field quantum key distribution (TF - QKD). The relevant results have been published online recently in the international authoritative journal physical review letters. Professor wang xiangbin and professor zhang qiang are the co-corresponding authors of the paper. The achievement successfully set a new world record for the longest transmission distance of quantum key distribution.




Channel loss is the most serious limiting factor in the long distance application of quantum key distribution (QKD). Tf-qkd USES single photon interference as an effective detection event to make the secure bit-rate decrease linearly with the square root of channel attenuation, and can even easily break the linear limit of QKD bit-rate in the case of no relay. However, the implementation condition of tf-qkd is rather harsh, which requires the single-photon level interference of two remote independent lasers, and requires the accurate estimation of the fast relative phase drift of long distance fiber links through the single-photon detection results.Channel loss is the most serious limiting factor in the long distance application of quantum key distribution (QKD). Tf-qkd USES single photon interference as an effective detection event to make the secure bit-rate decrease linearly with the square root of channel attenuation, and can even easily break the linear limit of QKD bit-rate in the case of no relay. However, the implementation condition of tf-qkd is rather harsh, which requires the single-photon level interference of two remote independent lasers, and requires the accurate estimation of the fast relative phase drift of long distance fiber links through the single-photon detection results.