Direct measurement of the $7s{}^2{S}_{1/2}\to$ $7p{}^2{P}_{3/2}$ transition frequency in ${}^{226}$Ra${}^{+}$

Abstract

We report a direct measurement of the $7s{}^2{S}_{1/2}\to$ $7p{}^2{P}_{3/2}$ 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.

4 pages, 5 figures