Direct measurement of the $7s\ ^2S_{1/2}\rightarrow$ $7p\ ^2P_{3/2}$ transition frequency in $^{226}$Ra$^{+}$

TL;DR

This paper reports a precise measurement of a specific atomic transition frequency in radium ion, resolving previous discrepancies and providing new data for atomic physics research.

Contribution

It provides the first direct measurement of the $7s ightarrow7p$ transition in $^{226}$Ra$^{+}$ using laser cooling and iodine referencing.

Findings

Transition frequency measured as 785722.11(3) GHz

Addresses a five-standard-deviation discrepancy in previous data

Demonstrates a method for high-precision atomic spectroscopy

Abstract

We report a direct measurement of the $7s\ ^2S_{1/2}\rightarrow$ $7p\ ^2P_{3/2}$ electric dipole transition frequency in $^{226}$Ra$^{+}$. With a single laser-cooled radium ion we determine the transition frequency to be 785722.11(3) GHz by directly driving the transition with frequency-doubled light and measuring the frequency of the undoubled light with an iodine reference. This measurement addresses a discrepancy of five combined standard deviations between previously reported values.