Many-body calculations of electric-dipole amplitudes for transitions between low-lying levels of Mg, Ca, and Sr

Abstract

To support efforts on cooling and trapping of alkaline-earth atoms and designs of atomic clocks, we performed ab initio relativistic many-body calculations of electric-dipole transition amplitudes between low-lying states of Mg, Ca, and Sr. In particular, we report amplitudes, and for 3 P o 2 → 1 D 2 transitions. For Ca, the reduced matrix element 4s4p 1 P o 1 ||D||4s 2 1 S 0 is in a good agreement with a high-precision experimental value deduced from photoassociation spectroscopy [Zinner et al., Phys. Rev. Lett. 85, 2292 ]. An estimated uncertainty of the calculated lifetime of the 3s3p 1 P o 1 state of Mg is a factor of three smaller than that of the most accurate experiment. Calculated binding energies reproduce experimental values within 0.1-0.2%.

Development of a configuration-interaction plus all-order method for atomic calculations

“…It was based on the Dirac-Fock code [37] and CI code [38]. This approach has been later applied to the calculation of atomic properties of various systems in a number of works (see [11,12,13,14,15,16,17,18] and references therein). In Refs.…”

“…[10]. The CI+MBPT method was applied to the calculation of atomic properties of various systems in a number of works (see [11,12,13,14,15,16,17,18,19,20] and references therein) and to the calculation of PNC amplitudes in Tl and Yb [21,22]. The strengths of the configurationinteraction method are broad applicability and all-order treatment of the valence-valence correlation corrections.…”

Accurate relativistic many-body calculations of van der Waals coefficients C8 and C10 for alkali-metal dimers

“…The virtual orbitals were determined with the help of a recurrent procedure [30]. One-electron basis sets of the following sizes were used on the stage DHF+Σ calculations: [33].…”

Relativistic effects in two valence-electron atoms and ions and the search for variation of the fine-structure constant

“…Note also that the CI+MBPT results presented in Table I are in good agreement with similar calculations in Refs. [28,29].…”