Precision measurement of Mg + 25 -ion D1 and D2 transition frequencies

Abstract

Precision measurement of Mg+ ion D1 and D2 doublet transition frequencies plays a significant part in the study of space-time variation of fundamental physical constant α. Here, we report a precision measurement of Mg+25 ion D1 and D2 doublet transition frequencies using the decoherence-assisted spectroscopy method with the full use of spontaneous emission signals to improve the detection sensitivity. We obtain the D1andD2 transition frequencies of Mg+25 with uncertainties of 0.12 and 0.24 MHz, respectively, which are one third of that in [A. Ozawa, Nat. Commun. 8, 44 (2017)2041-172310.1038/s41467-017-00067-9]. Simultaneously, we obtain the experimental and theoretical values of the Mg+25 hyperfine structure constants in this work. The differences between the measured magnetic dipole constants AP1/2=-102.87(8) MHz, AP3/2=-18.74(9) MHz and the theoretical values AP1/2=-102.02(94) MHz, AP3/2=-19.46(45) MHz are within 2σ, while the measured electric quadrupole constant BP3/2=24.54(45) MHz and the theoretical value of BP3/2=22.67(32) MHz shows a difference of more than 2σ, indicating that considerations of more physical effects in theoretical calculation, such as the possible capture of electron correlations, is required.