Highly charged Ag-like and In-like ions for the development of atomic clocks and the search forαvariation

Abstract

We carried out a detailed high-precision study of Ag-like ${\mathrm{Nd}}^{13+}$ and ${\mathrm{Sm}}^{15+}$ and In-like ${\mathrm{Ce}}^{9+}$, ${\mathrm{Pr}}^{10+}$, ${\mathrm{Nd}}^{11+}$, ${\mathrm{Sm}}^{13+}$, and ${\mathrm{Eu}}^{14+}$ highly charged ions. These ions were identified to be of particular interest for the development of ultra-accurate atomic clocks, the search for variation of the fine-structure constant $\ensuremath{\alpha}$, and quantum information [Safronova et al., Phys. Rev. Lett. 113, 030801 (2014)]. The 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, and magnetic-octupole reduced matrix elements, lifetimes, and sensitivity coefficients to $\ensuremath{\alpha}$ variation were calculated. A 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.