Contributing to TAI with a Secondary Representation of the SI Second

Abstract

We report the first contribution to the international atomic time (TAI) based on a secondary representation of the SI second. This work is done with the LNE-SYRTE FO2-Rb fountain frequency standard using the ${}^{87}$Rb ground state hyperfine transition. We describe FO2-Rb and how it is connected to local and international time scales. We report on local measurements of this frequency standard in the SI system, i.e. against primary frequency standards, down to a fractional uncertainty of $4.4\times 10^{-16}$, and on the establishment of the recommended value for the ${}^{87}$Rb hyperfine transition by the CIPM. We also report on the process that led to the participation of the FO2-Rb frequency standard to $CircularT$ and to the elaboration of TAI. This participation enables us to demonstrate absolute frequency measurement directly in terms of the SI second realized by the TAI ensemble with a statistical uncertainty of $1.1\times 10^{-16}$, therefore at the limit allowed by the accuracy of primary frequency standards. This work constitutes a demonstration of how other secondary representations, based on optical transitions, could also be used for TAI, and an investigation of a number of issues relevant to a future redefinition of the SI second.

13 pages, 10 figures, 3 tables, 80 references

References in corpus (13)

• Progress in Atomic Fountains at LNE-SYRTE
• Observation of the 1S0 - 3P0 clock transition in 27Al+
• Interference-filter-stabilized external-cavity diode lasers
• The absolute frequency of the 87Sr optical clock transition
• Improved tests of Local Position Invariance using 87Rb and 133Cs fountains
• Measuring the frequency of a Sr optical lattice clock using a 120-km coherent optical transfer
• One-Dimensional Optical Lattice Clock with a Fermionic 171Yb Isotope
• An Optical Lattice Clock with Spin-polarized 87Sr Atoms
• Evaluation of Doppler Shifts to Improve the Accuracy of Primary Atomic Fountain Clocks
• Evaluating and Minimizing Distributed Cavity Phase Errors in Atomic Clocks
• Tests of local position invariance using continuously running atomic clocks
• Frequency shift of hyperfine transitions due to blackbody radiation
• Demonstration of a Dual Alkali Rb/Cs Atomic Fountain Clock

Cited by in corpus (25)

• Searching for an oscillating massive scalar field as a dark matter candidate using atomic hyperfine frequency comparisons
• Violation of the equivalence principle from light scalar dark matter
• Advances in the accuracy, stability, and reliability of the PTB primary fountain clocks
• Frequency measurements of superradiance from the strontium clock transition
• Optical to microwave clock frequency ratios with a nearly continuous strontium optical lattice clock
• First international comparison of fountain primary frequency standards via a long distance optical fiber link
• Comparing a mercury optical lattice clock with microwave and optical frequency standards
• Improving cold-atom sensors with quantum entanglement: Prospects and challenges
• Atomic fountains and optical clocks at SYRTE: status and perspectives
• Evaluation of Long Term Performance of Continuously Running Atomic Fountains
• The unit of time: present and future directions
• Imaging Microwave and DC Magnetic Fields in a Vapor-Cell Rb Atomic Clock
• Lorentz-symmetry test at Planck-scale suppression with nucleons in a spin-polarized ${}^{133}$Cs cold atom clock
• Direct comparisons of European primary and secondary frequency standards via satellite techniques
• Survey of hyperfine structure measurements in alkali atoms
• Absolute frequency measurement of the 171Yb optical lattice clock at KRISS using TAI for over a year
• Demonstration of the nearly continuous operation of an ${}^{171}$Yb optical lattice clock for half a year
• Absolute frequency of ${}^{87}\mathrm{Sr}$ at $1.8\times 10^{-16}$ uncertainty by reference to remote Primary Frequency Standards
• Exploring the ultra-light to sub-MeV dark matter window with atomic clocks and co-magnetometers
• Space-Time Reference with an Optical Link
• Scattering of light dark matter in atomic clocks
• Absolute frequency measurement of a Yb optical clock at the limit of the Cs fountain
• Probing Supersymmetry Breaking Scale with Atomic Clocks
• Comment on "first accuracy evaluation of NIST-F2"
• 100-ns-level timing holdover after 12 years for rubidium atomic fountains