High-accuracy optical clocks based on group-16-like highly charged ions
Saleh O. Allehabi, Samuel M. Brewer, V. A. Dzuba, V. V. Flambaum, K. Beloy
Abstract
We identify laser-accessible transitions in group-16-like highly charged ions as candidates for high-accuracy optical clocks, including S-, Se-, and Te-like systems. For this class of ions, the ground $^{3}P_{J}$ fine-structure manifold exhibits irregular (nonmonotonic in $J$) energy ordering for large enough ionization degree. We consider the $|^{3}P_{2}\ensuremath{\rangle}\ensuremath{\longleftrightarrow}|^{3}P_{0}\ensuremath{\rangle}$ (ground to first-excited state) electric quadrupole transition, performing relativistic many-body calculations of several atomic properties important for optical clock development. All ions discussed are suitable for production in small-scale ion sources and lend themselves to sympathetic cooling and quantum-logic readout with singly charged ions.