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arXiv · 2109.00784

Implementation of field two-way quantum synchronization of distant clocks across a 7 km deployed fiber link

Runai Quan·Huibo Hong·Wenxiang Xue·Honglei Quan·Wenyu Zhao·Xiao Xiang·Yuting Liu·Mingtao Cao·Tao Liu·Shougang Zhang·Ruifang Dong
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Abstract

The two-way quantum clock synchronization has been shown not only providing femtosecond-level synchronization capability but also security against symmetric delay attacks, thus becoming a prospective method to compare and synchronize distant clocks with both enhanced precision and security. In this letter, a field test of two-way quantum synchronization between a H-maser and a Rb clock linked by a 7 km-long deployed fiber was implemented. Limited by the frequency stability of the Rb clock, the achieved time stability at 30 s was measured as 32 ps. By applying a fiber-optic microwave frequency transfer technology, the stability was improved by more than one-magnitude to 1.9 ps, even though the number of acquired photon pairs was only 1440 in 30 s due to the low sampling rate of the utilized coincidence measurement system. Such implementation demonstrates the high practicability of two-way quantum clock synchronization method for promoting the field applications.

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Runai Quan, Huibo Hong, Wenxiang Xue, Honglei Quan, Wenyu Zhao, Xiao Xiang, Yuting Liu, Mingtao Cao, Tao Liu, Shougang Zhang, Ruifang Dong. 2021-09-02. Implementation of field two-way quantum synchronization of distant clocks across a 7 km deployed fiber link. https://doi.org/10.1364/oe.451172

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