aqora

Relativistic Quantum Clocks

Maximilian P. E. Lock, Ivette Fuentes

arXiv:1609.09426Tutorials, schools, and workshops in the mathematical sciencesJan 1, 201712 citations

Distributed Time Tagging of Correlated Photons with White Rabbit–Syntonized Event Timers

Jacob E. Humberd, Noah Crum, Mohmad Junaid Ul Haq +4 more

We demonstrate distributed time tagging of correlated photons over fiber spools using MultiHarp time taggers syntonized via a White Rabbit switch and rubidium clocks, retrieving a stable remote correlation peak suitable for quantum networking applications.

Jan 1, 20260 citations

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

Runai Quan, Huibo Hong, Wenxiang Xue +8 more

The two-way quantum clock synchronization has been shown to provide femtosecond-level synchronization capability and security against symmetric delay attacks, thus becoming a prospective method to compare and synchronize distant clocks with enhanced precision and safety. 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 is implemented by using time-energy entangled photon-pair sources. Limited by the intrinsic frequency stability of the Rb clock, the achieved time stability at 30 s is measured as 32 ps. By applying a fiber-optic microwave frequency transfer technology to build frequency syntonization between the separated clocks, the limit set by the intrinsic frequency stability of the Rb clock is overcome. A significantly improved time stability of 1.9 ps at 30 s is achieved, which is mainly restrained by the low number of acquired photon pairs due to the low sampling rate of the utilized coincidence measurement system. Such implementation demonstrates the high practicability of the two-way quantum clock synchronization method for promoting field applications.The two-way quantum clock synchronization has been shown to provide femtosecond-level synchronization capability and security against symmetric delay attacks, thus becoming a prospective method to compare and synchronize distant clocks with enhanced precision and safety. 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 is implemented by using time-energy entangled photon-pair sources. Limited by the intrinsic frequency stability of the Rb clock, the achieved time stability at 30 s is measured as 32 ps. By applying a fiber-optic microwave frequency transfer technology to build frequency syntonization between the separated clocks, the limit set by the intrinsic frequency stability of the Rb clock is overcome. A significantly improved time stability of 1.9 ps at 30 s is achieved, which is mainly restrained by the low number of acquired photon pairs due to the low sampling rate of the utilized coincidence measurement system. Such implementation demonstrates the high practicability of the two-way quantum clock synchronization method for promoting field applications.

arXiv:2109.00784Optics ExpressMar 7, 202230 citations

Relativistic Calculations of Atomic Clock

B. K. Sahoo

Springer eBooksOct 24, 20163 citations

Entanglement-based clock syntonization for quantum key distribution networks: Demonstration over a 50 km-long link

Yoann Pelet, Grégory Sauder, Sébastien Tanzilli +2 more

We present the implementation of a time synchronization protocol as a part of an experimentally deployed entanglement-based quantum key distribution (QKD) link. The system is deployed over 48 km of optical fibers across the Métropole Côte d'Azur and enables secret cryptographic key exchange between two remote users, with an average rate of 7 kbps. We exploit the time correlation of paired photons generated by a high-quality source of energy-time entanglement implemented in the QKD link to synchronize two rubidium clocks located at the end stations. The level of stability achieved guarantees a time offset between the clocks under 12 ps at all time. We also show that this protocol requires less hardware than a typical synchronization protocol for QKD that would distribute a reference clock signal between the users.We present the implementation of a time synchronization protocol as a part of an experimentally deployed entanglement-based quantum key distribution (QKD) link. The system is deployed over 48 km of optical fibers across the Métropole Côte d'Azur and enables secret cryptographic key exchange between two remote users, with an average rate of 7 kbps. We exploit the time correlation of paired photons generated by a high-quality source of energy-time entanglement implemented in the QKD link to synchronize two rubidium clocks located at the end stations. The level of stability achieved guarantees a time offset between the clocks under 12 ps at all time. We also show that this protocol requires less hardware than a typical synchronization protocol for QKD that would distribute a reference clock signal between the users.

arXiv:2501.16796Applied Physics LettersApr 28, 202510 citations

Relativistic Calculations of Atomic Clock

B. K. Sahoo

Springer eBooksJan 1, 20154 citations

Method of relativistic syntonization of quantum clocks: experimental studies

Related papers

Method of relativistic syntonization of quantum clocks: experimental studies

Related papers