The frequency of the ultranarrow ${}^1{\text{S}}_0-{}^3{\text{P}}_2$ transition in ${}^{87}\text{Sr}$

Abstract

We determine the frequency of the ultranarrow ${}^{87}\text{Sr}$ ${}^1{\text{S}}_0-{}^3{\text{P}}_2$ transition by spectroscopy of an ultracold gas. This transition is referenced to four molecular iodine lines that are observed by Doppler-free saturation spectroscopy of hot iodine vapor. The frequency differences between the Sr and the I${}_2$ transitions are measured with an uncertainty of 250 kHz. The absolute frequency of the ${}^{87}\text{Sr}$ ${}^1{\text{S}}_0-{}^3{\text{P}}_2$ (${\text{F}}^{\prime }=7/2$) transition is 446648775(30) MHz and limited in accuracy by the iodine reference. This work prepares the use of the Sr ${}^1{\text{S}}_0-{}^3{\text{P}}_2$ transition for quantum simulation and computation.

8 pages, 6 figures