Enhanced laboratory sensitivity to variation of the fine-structure constant using highly-charged ions

TL;DR

This paper explores atomic systems with high sensitivity to potential variations in the fine-structure constant alpha, focusing on highly-charged ions suitable for optical clocks, and identifies promising candidates with enhanced sensitivity.

Contribution

The study introduces a method to identify highly-charged ions with increased sensitivity to alpha variation, combining high nuclear charge, ionization, and configuration differences.

Findings

Identified atomic systems with enhanced alpha-sensitivity in optical frequency range

Demonstrated the role of configuration crossing in maintaining optical frequencies

Highlighted promising ions with the largest alpha-sensitivity to date

Abstract

We study atomic systems that are in the frequency range of optical atomic clocks and have enhanced sensitivity to potential time-variation of the fine structure constant, alpha. The high sensitivity is due to coherent contributions from three factors: high nuclear charge Z, high ionization degree, and significant differences in the configuration composition of the states involved. Configuration crossing keeps the frequencies in the optical range despite the large ionization energies. We discuss a few promising examples that have the largest alpha-sensitivities seen in atomic systems.