Source: National Natural Science Foundation of China 

Grant No:11622434

Project: Optical frequence standard based on single trapped ion

Chief Specialist: Prof.Hua Guan

Abstract:

    Optical frequency standards based on single trapped ions are one kind of the frequency standards with highest precision. They have broad application in national metrology standard, national information trade and national defense construction etc. The applicant has been engaged in the research of optical frequency standard based on single trapped calcium ion. The main achievements are summarized as follows: (1) established the first calcium ion optical frequency standard in China. The comparison of two calcium ion optical frequency standards was completed, the uncertainty and stability are both reached E-17 level. The absolute frequency of clock transition in calcium ion was precisely measured twice, and the results were adopted by Consultative Committee for Time and Frequency (CCTF) and updated the recommended value of calcium ion optical frequency; (2) based on the established calcium ion optical frequency standard, two magic wavelengths were measured precisely. Promisingly, the measurement of these magic wavelengths paves the way to building all-optical trapped ion clocks. And the lifetime of D state of calcium ion was measured precisely. The applicant published 27 papers, include Phys. Rev. Lett. The 13 papers are the first-author or corresponding-author papers.
    Based on the series of experimental and theoretical accumulation established by the applicant, this project presents measured the differential scalar polarizability of clock transition of calcium ion, and the direct and indirect methods will be adopted. The measurement result is hopeful for reducing the uncertainty introduced by the differential scalar polarizability of clock transition from E-17 to E-18 even E-19.