Science and Technology Daily, Beijing, September 29th (Reporter Lin Lijun correspondent Chen Hanghang) On the 29th, the reporter learned from China Institute of Metrology that the data of strontium 87 atomic optical lattice clock (hereinafter referred to as strontium optical clock) developed by the institute was adopted by the international frequency standard working group for the first time and won the right to speak on the international issue of redefining seconds in the future.
The research of strontium atom optical lattice clock in China Institute of Metrology began in 2007, and was undertaken by an innovative team led by researcher Fang. From July 2065438 to July 2005, the team successfully completed the first system frequency shift evaluation and absolute frequency measurement of the strontium optical clock, with an accuracy of 2.3× 10- 16, equivalent to 65438+38 million years, not less than 1 second.
Fang told the Science and Technology Daily reporter that the strontium optical clock is the atomic clock with the highest frequency stability in the world, and it is also the most studied cold atomic optical lattice clock, which is two orders of magnitude higher than the cesium atomic fountain clock used in the current second definition, and is considered to be the most potential candidate for the new generation of second definition. At present, including China Metrology Institute, the strontium light clock data of 8 units, including the joint laboratory of the University of Colorado and the American Institute of Standards and Technology, the University of Tokyo, and the time and frequency standard laboratory of the Paris Observatory, have been adopted by the International Frequency Standards Working Group.
14 In September, the International Working Group on Frequency Standards decided to complete the definition of the new generation of seconds between 2025 and 2028. If the second is redefined with the new technology of light clock, it will have a far-reaching impact on global satellite positioning and navigation system, human exploration of the universe and study of physical laws.
"If we lose the right to speak in this respect, the existing system will not be able to reproduce the definition of seconds independently, and all related research and applications will lose their independence." Fang said that in the next step, the research team will further improve the accuracy of the strontium light clock.