Z. T. Xu, K. Deng,* H. Che, W. H. Yuan, J. Zhang, and Z. H. Lu†
MOE Key Laboratory of Fundamental Physical Quantities Measurement, Hubei Key Laboratory of Gravitation and Quantum Physics, School of Physics, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
(Received 28 August 2017; published 21 November 2017)
We report an experimental determination of the ground-state hyperfine constant A of the 25Mg+ ions by measuring the|S1/2,F =2,m =0 to|S1/2,F =3,m =0 transition (0-0transition) frequency of the two ground-state hyperfine energy levels. The frequency is measured by rf resonant method in a Paul trap under a magnetic field of about 0.1 mT. The result is A =−596.254 248 7(42) MHz. Different frequency shifts and uncertainties are evaluated. The main effect is quadratic Zeeman shift. Since the Paul trap is driven by rf on the electrodes, ac magnetic field can be induced by the rf at the site of the ion. The ac magnetic field causes quadratic Zeeman shift for ion frequency standards and also reduces the coherence time when the ion acts as a quantum bit. Precision measurement ofthis acmagnetic field can help evaluating therelated uncertainty when a single-ion optical clock is established on the trap.
DOI: 10.1103/PhysRevA.96.052507
