Quantum Clock Synchronization Network with Silicon-chip Dual-Pumped Entangled Photon Source

TL;DR

This paper presents a silicon-chip based quantum clock synchronization network using dual-pumped entangled photon sources, demonstrating high accuracy and resource efficiency over multiple users in a proof-of-principle experiment.

Contribution

It introduces a novel silicon-chip dual-pumped entangled photon source for quantum clock synchronization, enabling multi-user network with reduced channel resources and high timing precision.

Findings

Achieved low time deviations of 0.82 to 2.57 ps among users.

Demonstrated a multi-user QCS network over 10-25 km distances.

Reduced channel resource usage by about 30% compared to existing schemes.

Abstract

In this paper, we propose a quantum clock synchronization (QCS) network scheme with silicon-chip dual-pumped entangled photon source. This scheme couples two pump beams into the silicon-based waveguide, where degenerate and non-degenerate spontaneous four-wave mixing (SFWM) occurs, generating entanglement between one signal channel and three idler channels. The entangled photons are distributed to remote users through the wavelength division multiplexing strategy to construct an entanglement distribution network, and the round-trip QCS is adopted to realize a QCS network that can serve multiple users. A proof-of-principle QCS network experiment is implemented among the server and multiple users (Alice, Bob, and Charlie) for 11.1 hours, where Alice and Charlie are 10 km away from the server and Bob is 25 km away from the server. The lowest time deviations (TDEV) between the server and each user (Alice, Bob, and Charlie) are 1.57 ps, 0.82 ps and 2.57 ps at the average time of 8000 s, 8000 s and 800 s respectively. The results show that the QCS network scheme with dual-pumped SFWM photon source proposed by us achieves high accuracy, and the channel resources used by n users are reduced by about 30% compared with other round-trip QCS schemes.