High-accuracy optical clocks based on group 16-like highly charged ions

TL;DR

This paper proposes highly charged group 16-like ions as promising candidates for high-precision optical clocks, analyzing their atomic properties and potential for practical implementation.

Contribution

It identifies specific laser-accessible transitions in highly charged ions for optical clocks and provides detailed relativistic calculations of their properties.

Findings

Suitable for small-scale ion sources

Allow sympathetic cooling and quantum-logic readout

Exhibit irregular energy level ordering in the ground state

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 $|^3P_2\rangle \longleftrightarrow |^3P_0\rangle$ (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.