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

## TL;DR

This paper precisely measures the ultranarrow ${^1 ext{S}_0} - {^3 ext{P}_2}$ transition frequency in $^{87} ext{Sr}$ using iodine reference spectroscopy, enabling its application in quantum simulation and computation.

## Contribution

The study provides the first precise measurement of the $^{87} ext{Sr}$ transition frequency with 250 kHz uncertainty, referencing it to molecular iodine lines.

## Key findings

- Transition frequency is 446648775(30) MHz.
- Measurement uncertainty is 250 kHz.
- Results facilitate quantum simulation applications.

## 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 $^{87}\text{Sr}$ ${^{1}\text{S}_{0}} - {^{3}\text{P}_{2}}$ ($\text{F}'=7/2$) 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.