2026-03-23 京都大学
イッテルビウム原子の「内側」の電子にレーザー光を照射し、励起する様子。©️京都大学
＜関連情報＞
- https://www.kyoto-u.ac.jp/ja/research-news/2026-03-23-0
- https://www.kyoto-u.ac.jp/sites/default/files/2026-03/web_2603_Ishiyama-01ea455828fe34b585e077c3dbbbf355.pdf
- https://www.nature.com/articles/s41566-026-01857-8
中性イッテルビウムの内殻軌道時計遷移の精密分光法の精度が桁違いに向上 Orders-of-magnitude improvement in precision spectroscopy of an inner-shell orbital clock transition in neutral ytterbium
Taiki Ishiyama,Koki Ono,Hokuto Kawase,Tetsushi Takano,Reiji Asano,Ayaki Sunaga,Yasuhiro Yamamoto,Minoru Tanaka & Yoshiro Takahashi
Nature Photonics Published:20 March 2026
DOI:https://doi.org/10.1038/s41566-026-01857-8
Abstract
An inner-shell orbital clock transition 1S0 ↔ 4f135d6s2 (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 phenomena, such as ultralight dark matter, violation of local Lorentz invariance, and a new Yukawa potential between electrons and neutrons. Here we demonstrate almost two-orders-of-magnitude improvement in precision spectroscopy over previous reports on this transition, achieved by trapping atoms in a three-dimensional magic-wavelength optical lattice. In particular, we successfully observe the coherent Rabi oscillation, the relaxation dynamics of the excited state and the interorbital Feshbach resonance. To highlight the high precision of our spectroscopy, we carry out precise isotope shift measurements between five stable bosonic isotopes well below 10-Hz uncertainties, successfully setting bounds for a hypothetical boson mediating a force between electrons and neutrons. These results open up the way for various new physics search experiments and a wide range of applications to quantum science with this clock transition.
