HEFEI, May 13 (Xinhua) -- Experts used China's quantum satellite -- Quantum Experiments at Space Scale (QUESS) -- to verify quantum-secure time transfer for the first time, which laid a foundation for building a safe satellite navigation system.
The study published on Nature Physics was jointly accomplished by Professor Pan Jianwei from the University of Science and Technology of China and his colleagues.
High-precision time synchronization plays an important role in fundamental science and real-life applications, including navigation and positioning.
The current time synchronization techniques have shown to be vulnerable to sophisticated adversaries. Therefore, there is a compelling need for new methods to distribute high-precision time information securely.
The quantum communication technology can bring new solutions, said Pan. Based on the principle of quantum non-cloning, time transfer technology with a single photon as a carrier can fundamentally ensure the security of the signal transmission process.
In physics, the no-cloning theorem states that it is impossible to create an identical copy of an arbitrary unknown quantum state.
The research team led by Pan proposed a satellite-based quantum-secure time transfer (QSTT) scheme, in which a single photon is used as the carrier for both the time transfer and the secret-key generation, offering quantum-enhanced security for transferring the time signal and time information.
By using QUESS, experts performed a satellite-to-ground time synchronization using single-photon-level signals and achieved a quantum bit error rate of less than 1 percent and a time-transfer precision of 30 ps, Pan said.
China launched QUESS, nicknamed Micius after a 5th Century B.C. Chinese philosopher and scientist, on Aug. 16, 2016. Enditem
Picture of the experimental device
Xinhua, 2020-05-13, http://www.xinhuanet.com/english/2020-05/13/c_139054395.htm
On May 11, the Nature Publishing Group released Nature Publishing Index 2010 China, remarking “a dramatic rise in the quality of research being published by China”. University of Science and Technology of China is ranked 3rd of TOP 10 Institutions in Index 2010 China.
This article came from News Center of USTC.