Quadratic Zeeman and Electric Quadrupole Shifts in Highly Charged Ions

TL;DR

This paper develops a theoretical framework to analyze quadratic Zeeman and electric quadrupole shifts in highly charged ions, providing calculations relevant for precision spectroscopy and fundamental physics tests.

Contribution

It introduces a systematic approach using multiconfigurational Dirac-Fock calculations to evaluate these shifts in various highly charged ions.

Findings

Calculated quadratic Zeeman shift coefficients for Ca$^{14+}$, Ni$^{12+}$, and Xe$^{q+}$ ions.

Determined electric quadrupole moments for selected ionic states.

Provided data useful for optical clock development and fundamental physics experiments.

Abstract

Recent advances in high-precision spectroscopy of highly charged ions necessitate an understanding of energy shifts of ionic levels caused by external electric and magnetic fields. Beyond the well-known Stark and linear Zeeman shifts, trapped ions may also exhibit quadratic Zeeman and electric quadrupole shifts. In this contribution, we present a systematic approach for the theoretical analysis of these shifts for arbitrary many-electron ions. Based on the derived expressions and making use of the multiconfigurational Dirac-Fock approach, we performed calculations of quadratic Zeeman shift coefficients and quadrupole moments for various ionic states in Ca$^{14+}$, Ni$^{12+}$ and Xe$^{q+}$ ions. These ions attract particular interest for ongoing and future experiments in optical clocks and tests of fundamental physics.