Chinese researchers develop ytterbium lattice clock with record-breaking precision
Researchers at Chinese institutions have developed an optical lattice clock based on ytterbium-171 atoms achieving a systematic uncertainty of 1.1×10⁻¹⁸, among the most precise atomic clocks ever built. The clock uses an in-vacuum buildup cavity and differential frequency measurement between two identical units to minimize systematic errors. This advancement is significant for fundamental physics tests and will enable remote frequency comparisons between Shanghai and Wuhan.
A team led by Qiang Zhu and colleagues has constructed an ytterbium-171 optical lattice clock with a total systematic uncertainty of 1.1×10⁻¹⁸ and stability reaching 2.7×10⁻¹⁹ over an averaging time of 216,000 seconds. The design employs several technical innovations: an in-vacuum buildup cavity to enhance lattice light power, synchronous comparison between two identical clocks to evaluate systematic shifts, and a blackbody radiation shield in vacuum to characterize the BBR environment with an uncertainty contribution of 8.7×10⁻¹⁹. The magic frequency was determined to be 394,798,258.3(1) MHz, with lattice light shift controlled at 3×10⁻¹⁹ uncertainty. The research, submitted to the journal Metrologia, represents a significant achievement in optical clock precision and will facilitate remote frequency comparisons between two major Chinese cities.
What's missing
The paper does not discuss potential applications beyond frequency comparison (e.g., tests of fundamental physics, gravitational redshift measurements, or dark matter searches), nor does it compare performance metrics directly to other leading ytterbium or optical lattice clocks worldwide. The practical timeline for the Shanghai-Wuhan comparison and any collaborative institutions involved are not detailed.
What different sources said
- arXiv physicsCenter
Ytterbium lattice clock with uncertainty of $1.1\times 10^{-18}$ and instability of low $10^{-19}$
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