Atomic properties of Cd-like and Sn-like ions for the development of frequency standards and search for the variation of the fine-structure constant

TL;DR

This paper presents high-precision relativistic calculations of atomic properties for specific Cd-like and Sn-like ions, aiming to aid frequency standards and investigate the fine-structure constant's variability.

Contribution

It introduces a combined configuration interaction and coupled-cluster approach to compute atomic properties, including sensitivities to alpha variation, with detailed uncertainty analysis.

Findings

Calculated energies, transition wavelengths, and lifetimes for selected ions.

Determined sensitivity coefficients to alpha variation for these ions.

Compared theoretical energies with experimental data for validation.

Abstract

A high-precision relativistic calculations of Cd-like Nd$^{12+}$, Sm$^{14+}$ and Sn-like Pr$^{9+}$, Nd$^{10+}$ atomic properties is carried out using an approach that combines configuration interaction and a linearized coupled-cluster method. These ions have long-lived metastable states with transitions accessible by laser excitations, relatively simple electronic structure, high sensitivity to $\alpha$ variation, and stable isotopes. Breit and QED corrections were included into the calculations. Energies, transition wavelengths, electric- and magnetic-multipole reduced matrix elements, lifetimes, and sensitivity coefficients $q$ and $K$ to the variation of the fine-structure constant $\alpha$ were obtained. A detailed study of uncertainties was performed. Energies for similar Cd-like Ba$^{8+}$, La$^{9+}$, Ce$^{10+}$, Pr$^{11+}$ and Sn-like Ba$^{6+}$ ions were calculated and compared with experiment for further tests of the accuracy.