  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.
