The Land$\acute{e}$ $g$ factors for the $6S_{1/2}$ , $5D_{3/2,5/2}$ states of Ba${}^{+}$ ions

Abstract

The Land$\acute{e}$ $g$ factors of Ba${}^{+}$ are very important in high-precision measurement physics. The wave functions, energy levels, and Land$\acute{e}$ $g$ factors for the $6s$ ${}^2{S}_{1/2}$ and $5d$ ${}^2{D}_{3/2,5/2}$ states of Ba${}^{+}$ ions were calculated using the multi-configuration Dirac-Hartree-Fock (MCDHF) method and the Model-QED method. The contributions of the electron correlation effects and quantum electrodynamics (QED) effects were discussed in detail. The transition energies are in excellent agreement with the experimental results, with differences of approximately 5 cm${}^{-1}$. The presently calculated $g$ factor of 2.0024905(16) for the $6S_{1/2}$ agrees very well with the available experimental and theoretical results, with a difference at a level of 10${}^{-6}$. For the $5D_{3/2,5/2}$ states, the present results of 0.7993961(126) and 1.2003942(190) agree with the experimental results of 0.7993278(3) [\textcolor{blue}{Phys. Rev. A 54, 1199(1996)}] and 1.20036739(14) [\textcolor{blue}{Phys. Rev. Lett. 124, 193001 (2020)}] very well, with differences at the level of 10${}^{-5}$.