Related papers: One-Dimensional Optical Lattice Clock with a Fermi…
We report improved absolute frequency measurement of the $^{1}$S$_{0}-^{3}$P$_{0}$ transition of $^{171}$Yb at National Metrology Institute of Japan (NMIJ) by comparing the $^{171}$Yb optical lattice clock NMIJ-Yb1 with 13 Cs primary…
Singly-ionized ytterbium, with ultra-narrow optical clock transitions at 467 nm and 436 nm, is a convenient system for the realization of optical atomic clocks and tests of present-day variation of fundamental constants. We present the…
We report the absolute frequency measurement of the 5s2 1S0-5s5p 3P0 transition in 87Sr optical lattice clock (Sr1) at National Time Service Center (NTSC). Its systematic frequency shifts are evaluated carefully with a total relative…
We present a new evaluation of an 87Sr optical lattice clock using spin polarized atoms. The frequency of the 1S0-3P0 clock transition is found to be 429 228 004 229 873.6 Hz with a fractional accuracy of 2.6 10^{-15}, a value that is…
We observe a weakly allowed optical transition of atomic ytterbium from the ground state to the metastable state $4f^{13}5d6s^2 \: (J=2)$ for all five bosonic and two fermionic isotopes with resolved Zeeman and hyperfine structures. This…
The absolute frequency of the 1S0-3P0 clock transition of 87Sr has been measured to be 429 228 004 229 873.65 (37) Hz using lattice-confined atoms, where the fractional uncertainty of 8.6x10-16 represents one of the most accurate…
We report the first accuracy evaluation of an optical lattice clock based on the 1S0 - 3P0 transition of an alkaline earth boson, namely 88Sr atoms. This transition has been enabled using a static coupling magnetic field. The clock…
We report a stability below $7\times 10{}^{-17}$ of two independent optical lattice clocks operating with bosonic ${}^{88}$Sr isotope. The value (429228066418008.3(1.9)${}_{syst}$(0.9)${}_{stat}$~Hz) of the absolute frequency of the…
We have measured the absolute frequency of the optical lattice clock based on $^{87}$Sr at PTB with an uncertainty of $3.9\times 10^{-16}$ using two caesium fountain clocks. This is close to the accuracy of today's best realizations of the…
We report calculations designed to assess the ultimate precision of an atomic clock based on the 578 nm $6 ^1S_0 --> 6 ^3P^o_0$ transition in Yb atoms confined in an optical lattice trap. We find that this transition has a natural linewidth…
We report on the spectroscopy of the $5s^2 {}^1S_0 (F=9/2) \to 5s5p {}^3P_0 (F=9/2)$ clock transition of ${}^{87}{\rm Sr}$ atoms (natural linewidth of 1 mHz) trapped in a one-dimensional optical lattice. Recoilless transitions with a…
Optical clocks have extremely attractive applications in many fields, including time-frequency metrology, validation of fundamental physical principles, and relativistic geodesy. The 467 nm octupole transition in 171Yb+ ion exhibits…
We report an optical lattice clock with a total systematic uncertainty of $8.1 \times 10^{-19}$ in fractional frequency units, representing the lowest uncertainty of any clock to date. The clock relies on interrogating the ultra-narrow…
We report improved frequency ratio measurement with $^{87}$Sr and $^{171}$Yb optical lattice clocks at the National Metrology Institute of Japan (NMIJ). The $^{87}$Sr optical lattice clock is enhanced with several major modifications and is…
We report on the isotope shift between ${}^{88}$Sr and ${}^{87}$Sr on the ${}^1S_0 - {}^3P_0$ clock transitions. The interleaved operation of an optical lattice clock with two isotopes allows the canceling out of common perturbations, such…
We report direct measurements of the frequency ratio of the 642 THz ${}^2S_{1/2} (F=0)$--${}^2F_{7/2} (F=3)$ electric octupole transition in ${}^{171}\mathrm{Yb}^+$ and the 429 THz ${}^1S_0$--${}^3P_0$ transition in ${}^{87}\mathrm{Sr}$. A…
We present the experimental demonstration of non-destructive probing of the 1S0-3P0 clock transition probability in an optical lattice clock with 87Sr atoms. It is based on the phase shift induced by the atoms on a weak off-resonant laser…
We present an assessment of the (6s^{2})1S0 -> (6s7s)3P0 clock transition frequency in 199Hg with an uncertainty reduction of nearly three orders of magnitude and demonstrate an atomic quality factor, Q, of ~10^(14). The 199Hg atoms are…
Additional clock transitions of ytterbium atoms based on inner-shell orbital transition could benefit the search for new physics beyond the Standard Model. Observation of these transitions with high resolution is a prerequisite for making…
Optical lattice clocks with uncertainty and instability in the $10^{-17}$-range and below have so far been demonstrated exclusively using fermions. Here, we demonstrate a bosonic optical lattice clock with $3\times 10^{-18}$ instability and…