Connecting optical lattice clocks at 10 -18 uncertainty

Katori

N. Hinkley, Jeff A. Sherman, N. Lemke +8 more

Han-Ning Dai, Yu-Ao Chen

Hidetoshi Katori

The concept and recent progress of optical lattice clocks are reviewed. With the clock uncertainty of 10−17 in perspective, we discuss new challenges in optical lattice clocks and possible applications of such highly accurate and stable atomic clocks.

Stefano Origlia, Mysore Srinivas Pramod, Stephan Schiller +9 more

Optical clocks operated on satellites are expected to open up new opportunities in time transfer, geodesy, fundamental physics, and satellite navigation. Here we demonstrate an important first step towards this goal: a modular, compact, optical lattice clock (OLC) system that achieves $2.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$ fractional uncertainty. The clock is operated with bosonic strontium and improves the performance of bosonic OLCs by a factor of 30. This has important implications for future use of bosonic OLCs in fundamental physics and metrology. We make use of the clock's metrological performance to measure, with independent clocks, the isotope shift of the $^{1}S_{0}\ensuremath{\rightarrow}^{3}P_{0}$ transitions of $^{88}\mathrm{Sr}$ and $^{87}\mathrm{Sr}$, with an uncertainty of 12 mHz. The ratio of the transition frequencies is thus determined with $3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$ fractional uncertainty.

K. Yamanaka, Noriaki Ohmae, Ichiro Ushijima +2 more

We report on a frequency ratio measurement of a $^{199}\mathrm{Hg}$-based optical lattice clock referencing a $^{87}\mathrm{Sr}$-based clock. Evaluations of lattice light shift, including atomic-motion-dependent shift, enable us to achieve a total systematic uncertainty of $7.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$ for the Hg clock. The frequency ratio is measured to be ${\ensuremath{\nu}}_{\mathrm{Hg}}/{\ensuremath{\nu}}_{\mathrm{Sr}}=2.629\text{ }314\text{ }209\text{ }898\text{ }909\text{ }60(22)$ with a fractional uncertainty of $8.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}$, which is smaller than the uncertainty of the realization of the International System of Units (SI) second, i.e., the SI limit.