China News Service, Hefei, January 7 (Reporter Wu Lan) University of Science and Technology of China reported on the 7th that after more than two years of stability and safety testing, standardization research, and application demonstrations in different fields such as government affairs, finance and power, the school Pan Jianwei His colleagues and collaborators successfully verified the feasibility of building an integrated quantum communication network between the world and the earth.
On the 7th, the international academic journal "Nature" (Nature) magazine published a paper titled "A quantum communication network spanning 4600 kilometers".
The results of this paper were completed by Pan Jianwei and his colleagues Chen Yuao, Peng Chengzhi, etc. in cooperation with Wang Jianyu's research group at the Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Jinan Institute of Quantum Technology, and China Cable Network Co., Ltd.
According to reports, Chinese researchers have successfully constructed the prototype of a wide-area quantum secure communication network integrated with space and earth, laying a scientific and technological foundation for the realization of a global-covering quantum secure communication network in the future.
The research team built the world’s first integrated over 700 terrestrial fiber quantum key distribution (QKD) links and two satellite-to-ground freedoms based on the successful docking of the Quantum Secure Communication Beijing-Shanghai trunk line and the "Mozi" quantum satellite. The wide-area quantum communication network of the space high-speed QKD link realizes the large-scale, multi-user quantum key distribution of the satellite-ground integration with a ground span of 4,600 kilometers.
According to the different communication channels, quantum key distribution mainly has two realization methods: optical fiber and free space. Combining the two can realize a large-scale, full-coverage global quantum communication network.
At present, the world's integrated quantum communication network has access to more than 150 industry users including finance, power, and government affairs.
At the beginning of 2019, the State Grid Corporation of China established a quantum key distribution channel spanning 2,600 kilometers based on this network, which was the first engineering test of the feasibility of Xing-Ground Quantum Communication's actual business.
The related technologies developed in this work also laid the foundation for the miniaturization, low cost, and localization of quantum communication systems.
Recently, the team successfully developed a small ground station weighing about one hundred kilograms, and conducted satellite-to-earth quantum key distribution experiments with many international ground stations. It is expected that it can be transported by one person in the future; at the same time, the key distribution rate is guaranteed. We have successfully developed a miniaturized space quantum key distribution payload of several tens of kilograms. These achievements have also laid the foundation for the formation of an international technical standard for satellite quantum communications.
Under the guidance of a series of important quantum communications achievements such as China's "Mozi" and "Beijing-Shanghai trunk line", countries such as Europe and the United States are also accelerating the construction of quantum communications infrastructure.
At present, the prototype of a wide-area quantum communication network has basically taken shape. On this basis, in the future, it can further promote the wide application of quantum communication in the fields of finance, government affairs, national defense, and electronic information. The combination of terrestrial networks and quantum satellites provides a favorable basis for super-large-scale quantum interference experiments, and provides the possibility for the basic inspection of quantum gravity and large-scale interferometry for metrological applications. (Finish)