China has joined the global top-tier timekeeping club with a new optical clock that could help it play a leading role in redefining the second.
The clock’s key parameters, known as stability and uncertainty, both surpassed the level of 10 to the power of minus 19, a feat achieved by only a handful of labs worldwide, including the National Institute of Standards and Technology in the US and Germany’s national standards laboratory, the team wrote in the journal Metrologia this month.
Its precision exceeds the threshold required for redefining the second, potentially “allowing China to play a leading role in the effort”, according to state broadcaster CCTV.
“It lays a solid foundation for using optical clocks to test fundamental physics, improve next-generation satellite navigation and build a unified ultra-precise global time standard,” Dai told CCTV on March 7.
Optical clocks are the most precise timekeeping devices available. They use lasers to trap atoms such as strontium and rubidium at very low temperatures, and measure time from the frequency of light emitted as their electrons jump between energy levels.