Study of highly-charged Ag-like and In-like ions for the development of atomic clocks and search for $\alpha$-variation

TL;DR

This paper performs high-precision calculations on specific highly-charged ions to evaluate their suitability for atomic clocks and tests of fundamental constant variations, incorporating relativistic and QED effects.

Contribution

It introduces advanced computational methods for accurate property predictions of Ag-like and In-like ions relevant to atomic clock development and fundamental physics tests.

Findings

Accurate energy levels and transition data for selected ions.

Quantified sensitivity coefficients to alpha-variation.

Validated computational results against experimental data.

Abstract

We carried out detailed high-precision study of Ag-like Nd$^{13+}$, Sm$^{15+}$ and In-like Ce$^{9+}$, Pr$^{10+}$, Nd$^{11+}$, Sm$^{13+}$, Eu$^{14+}$ highly-charged ions. These ions were identified to be of particular interest to the development of ultra-accurate atomic clocks, search for variation of the fine-structure constant $\alpha$, and quantum information [Safronova et. al. Phys. Rev. Lett. 113, 030801 (2014)]. Relativistic linearized coupled-cluster method was used for Ag-like ion calculations, and a hybrid approach that combines configuration interaction and a variant of the coupled-cluster method was used for the In-like ion calculations. Breit and QED corrections were included. Energies, transition wavelengths, electric-dipole, electric-quadrupole, electric-octupole, magnetic-dipole, magnetic-quadrupole, magnetic-octupole reduced matrix elements, lifetimes, and sensitivity coefficients to $\alpha$-variation were calculated. Detailed study of various contributions was carried out to evaluate uncertainties of the final results. Energies for several similar "reference" ions, where the experimental values are available were calculated and compared with experiment for further tests of the accuracy.