Observation and Absolute Frequency Measurements of the 1S0 - 3P0 Optical Clock Transition in Neutral Ytterbium
C Hoyt, Zeb Barber, Christopher W. Oates, Scott A. Diddams, Tara M. Fortier, Leo W. Hollberg
We report the direct excitation of the highly forbidden (6s2) 1S0 - (6s6p) 3P0 optical transition in two odd isotopes of ytterbium. As the excitation laser frequency is scanned, absorption is seen by monitoring the depletion from an atomic cloud at ~70 microK in a magneto-optical trap. The F=1/2 - F=1/2 frequency in 171Yb is 518,295,836,608.5 (1.5) kHz. The F=5/2 - F=5/2 frequency in 173Yb is 518,294,576,858.6 (5.0) kHz. Made with a femtosecond-laser frequency comb calibrated by the NIST cesium fountain clock, these measurements represent over a million-fold reduction in uncertainty. The natural linewidth of these J=0 to J=0 transitions is calculated to be ~10 mHz, making them well-suited to support a new generation of optical atomic clocks based on confinement in an optical lattice.
atomic spectroscopy, optical cooling and trapping of atoms, spectroscopic techniques, time and frequency
, Barber, Z.
, Oates, C.
, Diddams, S.
, Fortier, T.
and Hollberg, L.
Observation and Absolute Frequency Measurements of the <sup>1</sup>S<sub>0</sub> - <sup>3</sup>P<sub>0</sub> Optical Clock Transition in Neutral Ytterbium, Physical Review Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50105
(Accessed December 11, 2023)