Frequency ratios of Sr, Yb and Hg based optical lattice clocks and their applications

Abstract

This article describes the recent progress of optical lattice clocks with neutral strontium (${}^{87}$Sr), ytterbium (${}^{171}$Yb) and mercury (${}^{199}$Hg) atoms. In particular, we present frequency comparison between the clocks locally via an optical frequency comb and between two Sr clocks at remote sites using a phase-stabilized fibre link. We first review cryogenic Sr optical lattice clocks that reduce the room-temperature blackbody radiation shift by two orders of magnitude and serve as a reference in the following clock comparisons. Similar physical properties of Sr and Yb atoms, such as transition wavelengths and vapour pressure, have allowed our development of a compatible clock for both species. A cryogenic Yb clock is evaluated by referencing a Sr clock. We also report on a Hg clock, which shows one order of magnitude less sensitivity to blackbody radiation, while its large nuclear charge makes the clock sensitive to the variation of fine-structure constant. Connecting all three types of clocks by an optical frequency comb, the ratios of the clock frequencies are determined with uncertainties smaller than possible through absolute frequency measurements. Finally, we describe a synchronous frequency comparison between two Sr-based remote clocks over a distance of 15 km between RIKEN and the University of Tokyo, as a step towards relativistic geodesy.

11 pages, 5 figures, invited review article in Comptes Rendus de Physique 2015

References in corpus (17)

• Sr lattice clock at 1x10^{-16} fractional uncertainty by remote optical evaluation with a Ca clock
• Frequency ratio of two optical clock transitions in ${}^{171}$Yb${}^{+}$ and constraints on the time-variation of fundamental constants
• Improved limit on a temporal variation of $m_p/m_e$ from comparisons of Yb${}^{+}$ and Cs atomic clocks
• New Limits on Coupling of Fundamental Constants to Gravity Using ${}^{87}$Sr Optical Lattice Clocks
• Multipolar theory of black-body radiation shift of atomic energy levels and its implications for optical lattice clocks
• Trapping of Neutral Mercury Atoms and Prospects for Optical Lattice Clocks
• Coherent optical frequency transfer at 5e-19 over a doubled 642 km fiber link
• Optical Lattice Induced Light Shifts in an Yb Atomic Clock
• High accuracy correction of blackbody radiation shift in an optical lattice clock
• An atomic clock with $1\times 10^{-18}$ room-temperature blackbody Stark uncertainty
• Measuring the frequency of a Sr optical lattice clock using a 120-km coherent optical transfer
• Lamb-Dicke spectroscopy of atoms in a hollow-core photonic crystal fibre
• Direct comparison of a Ca+ single ion clock against a Sr optical lattice clock
• Determination of the 5d6s 3D1 state lifetime and blackbody radiation clock shift in Yb
• Frequency ratio measurement of 171Yb and 87Sr optical lattice clocks
• Spin-1/2 Optical Lattice Clock
• Frequency Ratio of ${}^{199}$Hg and ${}^{87}$Sr Optical Lattice Clocks beyond the SI Limit

Cited by in corpus (3)

• Absolute frequency measurement of the 1S0 - 3P0 transition of 171Yb
• Optical frequency divider with division uncertainty at the 10^(-21) level
• All-polarization-maintaining, single-port Er:fiber comb for high-stability comparison of optical lattice clocks