69 research outputs found
Observation of the clock transition at 431 nm in Yb
We report on the observation of the transition at 431 nm in Yb by depleting atoms in
a magneto-optical trap formed by the intercombination
transition. The absolute frequency of the transition to the state is
determined to be ~kHz against physical realization of
Coordinated Universal Time maintained by the National Metrology Institute of
Japan with a frequency comb. The factor of the transition to the
state and the A hyperfine constant are measured to be and
1123.273(13)~MHz, respectively. More precise spectroscopy of this transition
can lead to searches for time variation of the fine structure constant and
searches for new physics with isotope shift measurements.Comment: 5 pages, 4 figure
Effect of entanglement on the decay dynamics of a pair of H(2p) atoms due to spontaneous emission
We have measured the coincidence time spectra of two Lyman-α photons emitted by a pair of H(2p) atoms in the photodissociation of H2 at the incident photon energy of 33.66 eV and at the hydrogen gas pressures of 0.40 and 0.02 Pa. The decay time constant at 0.02 Pa is approximately half the lifetime of a single H(2p) atom, 1.60 ns, while the decay time constant at 0.40 Pa is in agreement with the lifetime of a single H(2p) atom. It turns out that the decay faster than the lifetime of a single H(2p) atom originates from the entanglement in the pair of H(2p) atoms. We have demonstrated an effect of entanglement on atomic decayThe experiment was carried out under the approval of Photon Factory Program Advisory Committee for Proposal No. 2008G107. This work was partially supported by Grants- in-Aid for Scientific Research (C) (No. 19550011 and No. 22550008) from the Japan Society for the Promotion of Science. T.T. wishes to acknowledge the financial support by a Sasakawa Scientific Research Grant from the Japan Science Society, T.O. that of the Matsuo Foundation and Reimei Research Promotion Project of the Japan Atomic Energy Agency, and N.K. that of Research Foundation for Opto-Science and Technology. The authors are grateful to Dr. Kouichi Hosaka of the Department of Chemistry, Tokyo Institute of Technology, Dr. Atsushi Ichimura of the Institute of Space and Astronautical Science, JAXA, and Dr. James Harries of JAEA/SPring-8 for their fruitful discussions
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