First high-resolution spectroscopy of 201Hg+ hyperfine structure: a sensitive probe of nuclear structure and the hyperfine anomaly

TL;DR

This study presents the first high-resolution hyperfine structure spectroscopy of 201Hg+ using an atomic clock, achieving unprecedented precision and providing new insights into nuclear structure and hyperfine anomalies.

Contribution

It reports the first high-resolution measurement of 201Hg+ hyperfine structure and derives a new hyperfine anomaly value with improved accuracy.

Findings

Hyperfine interval measured to 29.954365821130 GHz

Hyperfine anomaly in 201Hg+ determined as -0.0016257(5)

Measurement precision improved by over 8 orders of magnitude

Abstract

Using 201Hg+ contained within a linear quadrupole rf ion trap that is part of an atomic clock, we report the first high-resolution spectroscopy on the hyperfine structure of 201Hg+. We measure the absolute ground state hyperfine interval to be 29.954365821130(171)(62)(10) GHz, more than 8 orders of magnitude improvement over the previous measurement. The first error estimate in parentheses is the statistical error in the shifted line center measurement, the second is systematic uncertainty, and the third is calibration uncertainty in the hydrogen maser reference standard. By comparison to the already accurately known ground state hyperfine interval for 199Hg+, we are able to derive a new value for the hyperfine anomaly in singly ionized mercury, Delta(S1/2, 199Hg+, 201Hg+) = -0.0016257(5), now limited by knowledge of the nuclear magnetic moment ratio.