Related papers: Portable laser-cooled ytterbium beam clock based o…
We report on a transportable optical clock, based on laser-cooled strontium atoms trapped in an optical lattice. The experimental apparatus is composed of a compact source of ultra-cold strontium atoms including a compact cooling laser…
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 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…
Atomic clocks have been transformational in science and technology, leading to innovations such as global positioning, advanced communications, and tests of fundamental constant variation. Next-generation optical atomic clocks can extend…
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…
An ultrastable optical clock based on neutral atoms trapped in an optical lattice is proposed. Complete control over the light shift is achieved by employing the $5s^2 {}^1S_0 \to 5s5p {}^3P_0$ transition of ${}^{87}{\rm Sr}$ atoms as a…
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…
Extra-laboratory atomic clocks are necessary for a wide array of applications (e.g. satellite-based navigation and communication). Building upon existing vapor cell and laser technologies, we describe an optical atomic clock, designed…
Optical clocks require an ultra-stable laser to probe and precisely measure the frequency of the narrow-linewidth clock transition. We introduce a portable ultraviolet (UV) laser system for use in an aluminum quantum logic clock,…
An atom exposed to an electric field will experience Stark shifts of its internal energy levels, proportional to their polarizabilities. In optical frequency metrology, the Stark shift due to background black-body radiation (BBR) modifies…
Accurate measurement of atomic temperature is fundamental for a wide range of applications, from quantum sensing to precision metrology. In optical lattice clocks, precise characterization of atomic temperature is required to minimize…
We report the direct excitation of the highly forbidden (6s^2) 1S0 - (6s6p) 3P0 optical transition in two odd isotopes of ytterbium. As the excitation laser frequency is scanned, absorption is detected by monitoring the depletion from an…
The superb precision of an atomic clock is derived from its stability. Atomic clocks based on optical (rather than microwave) frequencies are attractive because of their potential for high stability, which scales with operational frequency.…
A full evaluation of the uncertainty budget for the ytterbium ion optical clock at the National Physical Laboratory (NPL) was performed on the electric octupole (E3) $^2\mathrm{S}_{1/2}\,\rightarrow\, ^2\mathrm{F}_{7/2}$ transition. The…
Transition frequencies of atoms and ions are among the most accurately accessible quantities in nature, playing important roles in pushing the frontiers of science by testing fundamental laws of physics, in addition to a wide range of…
An inner-shell orbital clock transition $^1S_0 \leftrightarrow 4f^{13}5d6s^2 \: (J=2)$ in neutral ytterbium atoms has attracted much attention as a new optical frequency standard as well as a highly sensitive probe for several new physics…
We study the prospects of using transitions from the ytterbium ground state to metastable states $^3{\rm P}^{\rm o}_2$ at $E=19\,710.388~$cm$^{-1}$ and $4f^{13}5d6s^2\,(J=2)$ at $E=23\,188.518~$cm$^{-1}$ as clock transitions in an optical…
We describe a transportable optical lattice clock based on the $^1\mathrm{S}_0 \rightarrow {^3\mathrm{P}_0}$ transition of lattice-trapped $^{87}$Sr atoms with a total systematic uncertainty of $2.1 \times 10^{-18}$. The blackbody radiation…
We present the new absolute frequency measurement of ytterbium (171Yb) obtained at INRiM with the optical lattice clock IT-Yb1 against the cryogenic caesium (133Cs) fountain IT-CsF2, evaluated through a measurement campaign that lasted 14…
We use frequency comb-based optical two-way time-frequency transfer (O-TWTFT) to measure the optical frequency ratio of state-of-the-art ytterbium and strontium optical atomic clocks separated by a 1.5 km open-air link. Our free-space…