Researchers from a number of Chinese institutions have actually set a new world record by accomplishing a non-relay quantum key distribution over 1,002 km. This improvement, making use of twin-field QKD, ultra-low-loss fiber, and ultra-low-noise superconducting single-photon detectors, symbolizes a significant action towards high-speed intercity quantum interaction networks.
A point-to-point long-distance quantum crucial circulation (QKD) over a distance of 1,002 km has actually been accomplished by researchers from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), and their partners from Tsinghua University, Jinan Institute of Quantum Technology, and Shanghai Institute of Microsystem and Information Technology (SIMIT), CAS. This milestone not just sets a brand-new world record for non-relay QKD but likewise offers an option for high-speed intercity quantum interaction. The outcome was published in the journal Physical Review Letters on May 25th.
QKD is based on the principles of quantum mechanics and makes it possible for safe key circulation between two remote celebrations. When combined with the “one-time pad” file encryption technique, it can achieve the greatest level of security for private interaction. The distance of QKD has been restricted by factors such as the channel loss and system noise.
The twin-field QKD (TF-QKD) utilizing sending-or-not-sending (SNS) protocol was shown in the experiment, enhancing the relation in between the essential rate and channel transmittance from a direct η to its square root η. It can attain a much longer secure distance than standard QKD protocols.
A point-to-point long-distance quantum essential circulation (QKD) over a range of 1,002 km has been accomplished by researchers from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), and their collaborators from Tsinghua University, Jinan Institute of Quantum Technology, and Shanghai Institute of Microsystem and Information Technology (SIMIT), CAS. This milestone not only sets a new world record for non-relay QKD however also offers a service for high-speed intercity quantum communication. QKD is based on the concepts of quantum mechanics and makes it possible for safe key circulation between 2 remote parties.
To attain long-distance QKD, the research team worked together with Yangtze Optical Fibre and Cable Joint Stock Limited Company (YOFC) and utilized ultra-low-loss fiber based on pure silica core technology, which achieved an optimum attenuation of 0.16 dB/km. By carrying out numerous filters at temperature levels of 40 K and 2.2 K to suppress dark counts triggered by thermal radiation, the sound of the single-photon detectors was reduced to around 0.02 cps.
Based upon the previously mentioned technological developments, the team attained TF-QKD over a record distance of 1002 km, with a key rate of 0.0034 bps. This work not just verifies the expediency of the SNS-TF-QKD plan at incredibly long distances but also shows that this procedure can achieve high essential rates in many practical circumstances.
The success of this research study holds substantial ramifications for the improvement of secure quantum communication. It opens up new possibilities for long-distance quantum essential distribution and leads the way for the realization of high-speed intercity quantum interaction networks.
Reference: “Experimental Twin-Field Quantum Key Distribution over 1000 km Fiber Distance” by Yang Liu, Wei-Jun Zhang, Cong Jiang, Jiu-Peng Chen, Chi Zhang, Wen-Xin Pan, Di Ma, Hao Dong, Jia-Min Xiong, Cheng-Jun Zhang, Hao Li, Rui-Chun Wang, Jun Wu, Teng-Yun Chen, Lixing You, Xiang-Bin Wang, Qiang Zhang and Jian-Wei Pan, 25 May 2023, Physical Review Letters.DOI: 10.1103/ PhysRevLett.130.210801.