Details

Autor(en) / Beteiligte

• Dai, Hui
• Shen, Qi
• Wang, Chao-Ze
• Li, Shuang-Lin
• Liu, Wei-Yue
• Cai, Wen-Qi
• Liao, Sheng-Kai
• Ren, Ji-Gang
• Yin, Juan
• Chen, Yu-Ao
• Zhang, Qiang
• Xu, Feihu
• Peng, Cheng-Zhi
• Pan, Jian-Wei

Titel

Towards satellite-based quantum-secure time transfer

Ist Teil von

• Nature physics, 2020-08, Vol.16 (8), p.848-852

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2020

Quelle

Nature International Weekly Journal of Science

Beschreibungen/Notizen

• High-precision time synchronization for remote clocks plays an important role in fundamental science 1 – 3 and real-life applications 4 , 5 . However, current time synchronization techniques 6 , 7 have been shown to be vulnerable to sophisticated adversaries 8 . There is a compelling need for fundamentally new methods to distribute high-precision time information securely. Here, we propose a satellite-based quantum-secure time transfer (QSTT) scheme based on two-way quantum key distribution in free space and experimentally verify the key technologies of the scheme via the Micius quantum satellite. In QSTT, a quantum signal (for example, 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. We perform a satellite-to-ground time synchronization using single-photon-level signals and achieve a quantum bit error rate of less than 1%, a time data rate of 9 kHz and a time-transfer precision of 30 ps. These results offer possibilities towards an enhanced infrastructure for a time-transfer network, whose security stems from quantum physics. Transmitting the time signal and generating the secure key with the same carrier photon improves the security of a satellite-based quantum-secure time transfer protocol, which uses two-way quantum key distribution.