Precision measurement of M1 optical clock transition in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow><mml:mi>Ni</mml:mi></mml:mrow><mml:mrow><mml:mn>12</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math>
Shaolong Chen, Zhiqiang Zhou, Jiguang Li, Tingxian Zhang, Chengbin Li, Ting-Yun Shi, Yao Huang, Kelin Gao, Hua Guan
Abstract
Highly charged ions (HCIs) have drawn significant interest in quantum metrology and in the search for new physics. Among these, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msup><a:mrow><a:mi>Ni</a:mi></a:mrow><a:mrow><a:mn>12</a:mn><a:mo>+</a:mo></a:mrow></a:msup></a:math> is considered as one of the most promising candidates for the next generation of HCI optical clocks, due to its two E1-forbidden transitions M1 and E2, which occur in the visible spectral range. In this work, we used the Shanghai-Wuhan electron beam ion trap to perform a high-precision measurement of the M1 transition wavelength. Our approach involved an improved calibration scheme for the spectra, utilizing auxiliary <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:msup><b:mrow><b:mi>Ar</b:mi></b:mrow><b:mo>+</b:mo></b:msup></b:math> lines for calibration and correction. Our final measured result of the M1 transition wavelength demonstrates a fivefold improvement in accuracy compared to our previous findings, reaching the subpicometer level accuracy. In combination with our rigorous atomic-structure calculations to capture the electron correlations and relativistic effects, the quantum electrodynamic corrections were extracted. Published by the American Physical Society 2024