{"title":"Quantum clock synchronization with the silicon-chip based entangled photon source","authors":"Hui Han, Jia-ao Li, Bang-Ying Tang, Jia-hao Li, Jin-quan Huang, Huan Chen, Wan-Rong Yu, Bo Liu, Shu-hui Chen","doi":"10.1140/epjqt/s40507-025-00399-2","DOIUrl":null,"url":null,"abstract":"<div><p>Leveraging the properties of quantum entanglement and squeezing, quantum clock synchronization offers significant advantages in improving precision and security. For scalable quantum clock synchronization networks, developing an accurate time deviation analysis model is essential to characterize long-term timing stability and enable reliable deployment in real-world systems. This paper proposes a synchronization stability analysis model that establishes the theoretically achievable time deviation based on the Cramér-Rao lower bound. We experimentally validate this model using a round-trip quantum clock synchronization protocol over 50 km of fiber, employing an integrated silicon-photonic chip that generates frequency-entangled photon pairs via four-wave mixing. Results show a synchronization accuracy of 15.08 ps and a time deviation of 901 fs at an averaging time of 10,240 seconds, while our model analysis shows a standard deviation of 12.21 ps. This work provides a fundamental framework for building robust, large-scale quantum networks.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.6000,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00399-2","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"EPJ Quantum Technology","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1140/epjqt/s40507-025-00399-2","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"OPTICS","Score":null,"Total":0}
引用次数: 0
Abstract
Leveraging the properties of quantum entanglement and squeezing, quantum clock synchronization offers significant advantages in improving precision and security. For scalable quantum clock synchronization networks, developing an accurate time deviation analysis model is essential to characterize long-term timing stability and enable reliable deployment in real-world systems. This paper proposes a synchronization stability analysis model that establishes the theoretically achievable time deviation based on the Cramér-Rao lower bound. We experimentally validate this model using a round-trip quantum clock synchronization protocol over 50 km of fiber, employing an integrated silicon-photonic chip that generates frequency-entangled photon pairs via four-wave mixing. Results show a synchronization accuracy of 15.08 ps and a time deviation of 901 fs at an averaging time of 10,240 seconds, while our model analysis shows a standard deviation of 12.21 ps. This work provides a fundamental framework for building robust, large-scale quantum networks.
期刊介绍:
Driven by advances in technology and experimental capability, the last decade has seen the emergence of quantum technology: a new praxis for controlling the quantum world. It is now possible to engineer complex, multi-component systems that merge the once distinct fields of quantum optics and condensed matter physics.
EPJ Quantum Technology covers theoretical and experimental advances in subjects including but not limited to the following:
Quantum measurement, metrology and lithography
Quantum complex systems, networks and cellular automata
Quantum electromechanical systems
Quantum optomechanical systems
Quantum machines, engineering and nanorobotics
Quantum control theory
Quantum information, communication and computation
Quantum thermodynamics
Quantum metamaterials
The effect of Casimir forces on micro- and nano-electromechanical systems
Quantum biology
Quantum sensing
Hybrid quantum systems
Quantum simulations.