BEIJING, Feb 12 (BelTA\/APP): Chinese researchers have developed the world’s first large-scale quantum key distribution (QKD) network based on integrated photonic quantum chips, according to a study published on Thursday in the journal Nature.<\/p>\n
This network supports parallel communication involving 20 users, while covering a total distance of 3,700 kilometers and achieving a global leading level in terms of both user scale and network span.<\/p>\n
QKD uses quantum states to transmit keys for information encryption, thus ensuring communication security. Twin-field QKD, which is suitable for long-distance quantum communication and supports resource sharing at the detector end, has emerged as an advanced form of QKD technology.<\/p>\n
However, due to the extremely high performance requirements of light sources and modulation devices, the necessary hardware chip integration is difficult to achieve. As a result, this technology is mostly used in point-to-point QKD, while the realization of a multi-user, large-scale network system faces considerable challenges.<\/p>\n
A team led by Wang Jianwei from Peking University’s School of Physics, and Gong Qihuang, academician of the Chinese Academy of Sciences, has developed a series of high-performance, fully integrated photonic quantum chips. On the basis of these chips, they constructed a twin-field QKD network comprising 20 quantum chip nodes.<\/p>\n
According to Wang, this is the world’s first demonstration of a QKD network based on photonic quantum chips in over two decades. Experiments showed these chips exhibit high uniformity during wafer-level fabrication, enabling low-cost mass production. It lays a technical foundation for building QKD networks featuring longer distances and more users.<\/p>\n
“Chip-based QKD networks represent a significant step toward system miniaturization and device practicality,” Wang said, adding that high-performance and low-cost photonic quantum chips hold significant potential in advancing the practical application and large-scale deployment of quantum networks.<\/p>\n
Reviewers from Nature noted that this work represents a significant advancement in quantum chip and quantum network technology, while the demonstrated quantum chip network exhibits remarkable scalability. “The article is undoubtedly of high impact for the quantum communication community,” a reviewer commented.<\/p>\n
Gong said this achievement provides a viable solution for constructing large-scale quantum communication chip networks and will promote the miniaturization, practical application and large-scale development of quantum communication systems.<\/p>\n