Optical atomic clocks represent the state of the art in the frontier of modern measurement
science. In this article a detailed review on the development of optical atomic clocks that are …

Singly ionized ytterbium, with ultranarrow optical clock transitions at 467 and 436 nm, is a
convenient system for the realization of optical atomic clocks and tests of present-day …

For the past 50 years, atomic standards based on the frequency of the cesium ground-state
hyperfine transition have been the most accurate time pieces in the world. We now report a …

We present a detailed experimental and theoretical study of the effect of nuclear spin on the
performance of optical lattice clocks. With a state-mixing theory including spin-orbit and …

We report on the first absolute transition frequency measurement at the 10-15 level with a
single, laser-cooled Ca+ 40 ion in a linear Paul trap. For this measurement, a frequency …

We describe experiments and measurements on a trapped and laser-cooled single ion of
Sr+ 88 which, when probed on its reference 5 s S 1/2 2→ 4 d D 5/2 2 transition at 445 THz …

An ion trap of the end-cap design was built recently at the National Research Council of
Canada for improved control of the 88 Sr+ single-ion optical frequency standard systematic …

With ultracold Sr 87 confined in a magic wavelength optical lattice, we present the most
precise study (2.8 Hz statistical uncertainty) to date of the S 0 1-P 0 3 optical clock transition …

We compare the frequencies of the 6 s S 1/2 2 (F= 0)→ 5 d D 3/2 2 (F= 2) reference
transition in Yb+ 171 for two single ions stored in independent traps. The quadrupole …

The electric quadrupole shift is presently the most significant source of uncertainty on the
systematic shifts for several single-ion optical frequency standards. We present a simple …