RIKEN Center for Advanced Photonics Nuclear Laser Spectroscopy Research Unit
Unit Leader: Atsushi Yamaguchi (D. Sci.)
Research Summary
Our daily lives, from smartphones to car navigation, rely heavily on accurate clocks. Currently, the most accurate are atomic clocks, which utilize the energy levels of electrons. Aiming for even higher accuracy, we are developing a nuclear clock that utilizes the energy levels of the atomic nucleus instead. Since the nucleus is highly immune to external noise, this clock is expected to surpass existing atomic clocks. Recently, we successfully trapped thorium ions—to be used in the nuclear clock—and developed laser spectroscopy techniques to precisely control their motion and internal states. We aim to apply nuclear clocks not only for frequency standards but also to unlock mysteries of the universe, such as searching for dark matter.
Main Research Fields
- Interdisciplinary Science & Engineering
Related Research Fields
- Engineering
- Physics
Keywords
- Quantum electronics
- Quantum metrology
- Nuclear clock
- Thorium-229
- Ion trap
Selected Publications
Papers with an asterisk(*) are based on research conducted outside of RIKEN.
- 1.
*Shigekawa, Y., Yamaguchi, A., Tokoi, K., Sato, N., Kikunaga, H., Shirasaki, K., Kasamatsu, Y., Wada, M., and Haba, H.:
"Lifetime of the singly charged 229Th nuclear isomer"
Nat. Phys. (2026). - 2.
*Hiraki, T., Okai, K., Bartokos, M., Beeks, K., Fujimoto, H., Fukunaga, Y., Haba, H., Kasamatsu, Y., Kitao, S., Leitner, A., Masuda, T., Guan, M., Nagasawa, N., Ogake, R., Pimon, M., Pressler, M., Sasao, N., Schaden, F., Schumm, T., Seto, M., Shigekawa, Y., Shimizu, K., Sikorsky, T., Tamasaku, K., Takatori, S., Watanabe, T., Yamaguchi, A., Yoda, Y., Yoshimi, A., and Yoshimura, K.:
"Controlling 229Th isomeric state population in a VUV transparent crystal"
Nat. Commun. 15, 5536 (2024). - 3.
*Yamaguchi, A., Shigekawa, Y., Haba, H., Kikunaga, H., Shirasaki, K., Wada, M., and Katori, H.:
"Laser spectroscopy of triply charged 229Th isomer for a nuclear clock"
Nature 629, 62 (2024). - 4.
*Yamaguchi, A., Muramatsu, H., Hayashi, T., Yuasa, N., Nakamura, K., Takimoto, M., Haba, H., Konashi, K., Watanabe, M., Kikunaga, H., Maehata, K., Yamasaki, N. Y., and Mitsuda, K.:
"Energy of the 229Th Nuclear Clock Isomer Determined by Absolute -ray Energy Difference"
Phys. Rev. Lett. 123, 222501 (2019). - 5.
*Masuda, T., Yoshimi, A., Fujieda, A., Fujimoto, H., Haba, H., Hara, H., Hiraki, T., Kaino, H., Kasamatsu, Y., Kitao, S., Konashi, K., Miyamoto, Y., Okai, K., Okubo, S., Sasao, N., Seto, M., Schumm, T., Shigekawa, Y., Suzuki, K., Stellmer, S., Tamasaku, K., Uetake, S., Watanabe, M., Watanabe, T., Yasuda, Y., Yamaguchi, A., Yoda, Y., Yokokita, T., Yoshimura, M., and Yoshimura, K.:
"X-ray pumping of the 229Th nuclear clock isomer"
Nature 573, 238 (2019).
Lab Members
Principal investigator
- Atsushi Yamaguchi
- Unit Leader
Contact Information
2-1 Hirosawa,
Wako, Saitama
351-0198, Japan
Email: atsushi.yamaguchi.fv@riken.jp