Recently, Pan Jianwei and Xu Feihu of the University of Science and Technology of China cooperated with researchers from Shanghai Institute of Microsystems, Jinan Quantum Technology Research Institute, Harbin Institute of Technology and other units to develop high-fidelity integrated photonics quantum state control, high count rate superconducting single Key technologies such as photon detection have achieved real-time quantum key distribution at a 100-megabit rate for the first time in the world. The experimental results have increased the previous record of coding rate by an order of magnitude. The achievement was published online in the international academic journal Nature-Photonics on March 14.

This research is the first to achieve real-time quantum key distribution at a 100-megabit rate in the world, and the experimental results have increased the previous record of coding rate by an order of magnitude. Image source: CCTV news client

Quantum key distribution (QKD) is based on the basic principles of quantum mechanics, which can realize unconditionally secure and secure communication in principle. Improving the coding rate of QKD plays a vital role in its practical application. The high bit rate can provide services for more users and realize applications with high bandwidth requirements such as big data sharing and distributed storage encryption. Previously, the highest real-time bit rate in the world was 10Mb/s (under 10km standard fiber channel). In order to achieve a higher key rate, it is necessary to solve technical bottlenecks such as the sending end, receiving end and post-processing of the system.

The research group of Pan Jianwei and Xu Feihu has developed high-speed and high-fidelity polarization state modulation technology on an integrated photonic chip. The system repetition frequency reaches 2.5GHz, and the qubit error rate is better than 0.35%. High count rate, high-efficiency single-photon detection; at the same time, the research group developed polarization feedback control, high-speed post-processing modules, etc. On the basis of the above-mentioned technical breakthroughs, the research team achieved a key rate of 115.8 Mb/s over a 10-kilometer standard optical fiber channel, which was about an order of magnitude higher than the previous record; The code rate exceeds 200b/s. The above research results show that quantum key distribution can realize real-time key distribution at a 100-megabit rate and meet the needs of high-bandwidth communication, which is of great significance to the large-scale practical application of quantum communication in the future.

(Original title: "Chinese Scientists Realize 100-Mbit Rate Quantum Key Distribution")