An extrapolation method for polarizability assessments of ion-based optical clocks

TL;DR

This paper introduces a numerical extrapolation method for polarizability measurements in ion-based optical clocks, improving accuracy in assessing blackbody radiation shifts by combining experimental data with atomic structure calculations.

Contribution

The method explicitly models frequency dependence without ad hoc functions and integrates atomic structure calculations to enhance measurement extrapolation.

Findings

Applied to Al+, Lu+, and Yb+ ions, demonstrating improved extrapolation accuracy.

Provides indicators for data inconsistencies and theory-experiment discrepancies.

Enhances assessment of blackbody radiation shifts in optical clocks.

Abstract

We present a numerical method for extrapolating polarizability measurements to dc as done in the assessment of blackbody radiation shifts for ion-based clocks. The method explicitly accounts for the frequency dependence of relevant atomic transitions without introducing an ad hoc modelling function. It incorporates \emph{a priori} atomic structure calculations, which allows measurements to be augmented by calculations if there is insufficient data to make a purely measurement based estimate. The method also provides indicators of inconsistencies between theory and experiment or inadequacies of the data for making an extrapolation. We use results from Al$^+$, Lu$^+$, and Yb$^+$ to illustrate features of the method.