1.2k citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- The University of TokyoJP139 papers
- Nagoya UniversityJP69 papers
- Kyoto UniversityJP67 papers
- Tokyo Institute of TechnologyJP66 papers
- National Astronomical Observatory of JapanJP63 papers
- The University of OsakaJP57 papers
- Institute of Space and Astronautical ScienceJP54 papers
- Louisiana State UniversityUS53 papers
- High Energy Accelerator Research OrganizationJP50 papers
- Japan Science and Technology AgencyJP47 papers
- Japan Aerospace Exploration AgencyJP45 papers
- Centre National de la Recherche ScientifiqueFR40 papers
23 papers · 1 filter
Roadmap towards the redefinition of the second
N. Dimarcq, M. Gertsvolf, G. Mileti +34
This paper outlines the roadmap towards the redefinition of the second, which was recently updated by the CCTF Task Force created by the CCTF in 2020. The main achievements and the…
Absolute frequency of at uncertainty by reference to remote Primary Frequency Standards
Nils Nemitz, Tadahiro Gotoh, Fumimaru Nakagawa +4
The optical lattice clock NICT-Sr1 regularly reports calibration measurements of the international timescale TAI. By comparing measurement results to the reports of eight Primary F…
Frequency ratio of an In ion clock and a Sr optical lattice clock
Nozomi Ohtsubo, Ying Li, Nils Nemitz +4
We report on the first frequency ratio measurement of an In+ single ion clock and a Sr optical lattice clock. A hydrogen maser serves as a reference oscillator to me…
First observation with global network of optical atomic clocks aimed for a dark matter detection
P. Wcisło, P. Ablewski, K. Beloy +19
We report on the first earth-scale quantum sensor network based on optical atomic clocks aimed at dark matter (DM) detection. Exploiting differences in the susceptibilities to the…
Months-long real-time generation of a time scale based on an optical clock
Hidekazu Hachisu, Fumimaru Nakagawa, Yuko Hanado +1
Time scales consistently provide precise time stamps and time intervals by combining atomic frequency standards with a reliable local oscillator. Optical frequency standards, howev…
Prospects for Polar Molecular Ion Optical Probe of Varying Proton-Electron Mass Ratio
Mark G. Kokish, Patrick R. Stollenwerk, Masatoshi Kajita +1
Molecules with deep vibrational potential wells provide optical intervals sensitive to variation in the proton-electron mass ratio (). On one hand, polar molecules are of intere…
Frequency measurement of the clock transition of an indium ion sympathetically-cooled in a linear trap
Nozomi Ohtsubo, Ying Li, Kensuke Matsubara +2
We report frequency measurement of the clock transition in an 115In+ ion sympathetically-cooled with Ca+ ions in a linear rf trap. The Ca+ ions are used as a probe of the external…
Calculations of electronic properties and vibrational parameters of alkaline-earth lithides: MgLi^+ and CaLi^+
Renu Bala, H. S. Nataraj, Minori Abe +1
The ^1Σ^+ electronic ground states of MgLi^+ and CaLi^+ molecular ions are investigated for their spectroscopic constants and properties such as the dipole- and quadrupole moments,…
Ab initio calculations of spectroscopic constants and properties of BeLi +
Renu Bala, H. S. Nataraj
We have calculated the ground state spectroscopic constants and the molecular properties, of a molecular ion BeLi + , such as dipole moment, quadrupole moment and dipole polarizabi…
Two-step pulse observation to improve resonance contrast for coherent population trapping atomic clock
Yuichiro Yano, Shigeyoshi Goka, Masatoshi Kajita
We study resonance contrast by a two-step pulse observation method to enhance the frequency stability of coherent population trapping (CPT) atomic clocks. The proposed method is a…
Absolute frequency measurement with uncertainty below using International Atomic Time
Hidekazu Hachisu, Gérard Petit, Tetsuya Ido
The absolute frequency of the clock transition measured in 2015 was reevaluated using an improved frequency link to the SI second. The scale interval of Internation…
Accuracy estimation of the 16O2+ transition frequencies targeting the search for the variation in mp/me
Masatoshi Kajita
The precise measurement of molecular vibrational transition frequencies is useful in the search for variation in the proton-to-electron mass ratio μ. Homonuclear diatomic molecules…
Intermittent optical frequency measurements to reduce the dead time uncertainty of frequency link
Hidekazu Hachisu, Tetsuya Ido
The absolute frequency of the lattice clock transition was evaluated with an uncertainty of using a frequency link to the international atomic…
Two-step pulse observation for Raman-Ramsey coherent population trapping atomic clocks
Yuichiro Yano, Shigeyoshi Goka, Masatoshi Kajita
We propose a two-step pulse observation method to enhance frequency stability for coherent population trapping (CPT) atomic clocks. The proposed method is a Raman-Ramsey scheme wit…
Generation of vacuum ultraviolet radiation by intracavity high-harmonic generation toward state detection of single trapped ions
Kentaro Wakui, Kazuhiro Hayasaka, Tetsuya Ido
VUV radiation around 159 nm is obtained toward direct excitation of a single trapped In ion. An efficient fluoride-based VUV output-coupler is employed for intracavit…
Carrier-phase Two-Way Satellite Frequency Transfer over a Very Long Baseline
M Fujieda, D Piester, T Gotoh +3
In this paper we report that carrier-phase two-way satellite time and frequency transfer (TWSTFT) was successfully demonstrated over a very long baseline of 9,000 km, established b…
Direct comparison of optical lattice clocks with an intercontinental baseline of 9 000 km
H. Hachisu, M. Fujieda, S. Nagano +9
We have demonstrated a direct frequency comparison between two lattice clocks operated in intercontinentally separated laboratories in real time. Two-way satellite…
Direct comparison of a Ca+ single ion clock against a Sr optical lattice clock
Kensuke Matsubara, Hidekazu Hachisu, Ying Li +7
Optical frequency comparison of the 40Ca+ clock transition ν_{Ca} (2S1/2-2D5/2, 729nm) against the 87Sr optical lattice clock transition ν_{Sr}(1S0-3P0, 698nm) has resulted in a fr…
Stability Transfer between Two Clock Lasers Operating at Different Wavelengths for Absolute Frequency Measurement of Clock Transition in 87Sr
A. Yamaguchi, N. Shiga, S. Nagano +5
We demonstrated transferring the stability of one highly stable clock laser operating at 729 nm to another less stable laser operating at 698 nm. The two different wavelengths were…
Direct Comparison of Distant Optical Lattice Clocks at the Uncertainty
Atsushi Yamaguchi, Miho Fujieda, Motohiro Kumagai +7
Fiber-based remote comparison of Sr lattice clocks in 24 km distant laboratories is demonstrated. The instability of the comparison reaches over an averagi…
Locking Local Oscillator Phase to the Atomic Phase via Weak Measurement
Nobuyasu Shiga, Makoto Takeuchi
We propose a new method to reduce the frequency noise of a Local Oscillator (LO) to the level of white phase noise by maintaining (not destroying by projective measurement) the coh…
Buffer gas induced collision shift for the Sr clock transition
Nobuyasu Shiga, Ying Li, Hiroyuki Ito +5
Precision saturation spectroscopy of the is performed in a vapor cell filled with various rare gas including He, Ne, Ar, and Xe. By continuously calibra…
Suppression of inelastic collisions of polar state molecules in an electrostatic field
Alexander V. Avdeenkov, Masatoshi Kajita, John L. Bohn
Collisions of polar state molecules at ultralow energies are considered, within a model that accounts for long-range dipole-dipole interactions, plus rotation of the molecu…