[20p-F202-1~9] 1.5 Instrumentation, measurement and Metrology

[20p-F202-4] Update of the CIPM recommended frequency of the In⁺ clock transition

〇Ying Li¹, Nozomi Ohtsubo¹, Kensuke Matsubara¹, Kazuhiro Hayasaka¹, Tetsuya Ido¹ (1.NICT)

Keywords:Optical frequency standard

We report on a new frequency measurement of the ¹S₀-³P₀ clock transition in ¹¹⁵In⁺ at 237 nm. The single In⁺ is prepared by sympathetic cooling with two Ca⁺ ions in a linear trap. The frequency is determined to be 1 267 402 452 901 049.1 (6.9) Hz by averaging 36 measurements referenced to the UTC(NICT) and a Sr optical lattice clock. The measurement provides a new frequency value. And the recommended value of In ⁺ ion clock transition frequency is updated by the CIPM.