Space-Time Engineering Research Team

Clocks have served as a tool to share time, based on universal periodic phenomena; humankind relied upon the rotation of the earth from antiquity. The radiation from an atom provides us with far more accurate periodicity. The state-of-the-art atomic clocks sense the relativistic space-time curved by gravity, which reveal the difficulty of sharing time with others. Moreover, such clocks may be used to investigate the constancy of fundamental constants, where the foundation of the atomic clocks is anchored.

Optical lattice clocks raised the possibility of ultra-stable and accurate timekeeping by applying the "magic wavelength" protocol on optical lattices. Since the proposal of the scheme in 2001, the optical lattice clocks are being developed by more than 20 groups in the world, and the clocks are surpassing the uncertainty of the current SI second, becoming one of the most promising candidates for the future redefinition of the second.

Our team develops highly precise and transportable optical lattice clocks capable of long time operation by introducing advanced techniques in the field of atomic physics and quantum optics; we thus explore applications of "space-time engineering" that fully utilize the novel time resource provided by such clocks. For example, a transportable ultraprecise atomic clock, which may be taken out into the field, will function as a gravitational potential meter. We experimentally investigate the impact of such relativistic geodesy as a newer role for clocks in the future.

Research Fields

Physics / Engineering

Research Subjects

• Development of optical lattice clocks with superb precision
• Investigation of the constancy of fundamental constants using atomic clocks
• Development of gravitational potential meter using high precision clocks
• Quantum information technology based on ultracold neutral atoms
• Exploratory research on relativistic geodesy

Publications

1. Hidetoshi Katori, "Optical lattice clocks and quantum metrology," Nature Photon 5, 203-210 (2011)
2. Masao Takamoto, Tetsushi Takano, and Hidetoshi Katori, "Frequency comparison of optical lattice clocks beyond the Dick limit," Nature Photon. 5, 288-292 (2011)
3. Atsushi Yamaguchi, Miho Fujieda, Motohiro Kumagai, Hidekazu Hachisu, Shigeo Nagano, Ying Li, Tetsuya Ido, Tetsushi Takano, Masao Takamoto, and Hidetoshi Katori, "Direct Comparison of Distant Optical Lattice Clocks at the10^-16 Uncertainty," Appl. Phys. Exp. 4, 082203 (2011)
4. H. Katori, K. Hashiguchi, E. Yu. Il'inova, V. D. Ovsiannikov, "Magic Wavelength to Make Optical Lattice Clocks Insensitive to Atomic Motion," Phys. Rev. Lett. 103, 153004 (2009)
5. M. Takamoto, H. Katori, S. I. Marmo, V. D. Ovsiannikov, and V. G. Pal'chikov, "Prospects for Optical Clocks with a Blue-Detuned Lattice," Phys. Rev. Lett. 102, 063002 (2009)
6. Tomoya Akatsuka, Masao Takamoto, and Hidetoshi Katori, "Optical lattice clocks with non-interacting bosons and fermions," Nat. Phys. 4, 954-959 (2008)
7. H. Hachisu, K. Miyagishi, S. G. Porsev, A. Derevianko, V. D. Ovsiannikov, V. G. Pal’chikov, M. Takamoto, and H. Katori, "Trapping of Neutral Mercury Atoms and Prospects for Optical Lattice Clocks," Phys. Rev. Lett. 100, 053001 (2008)
8. M. Takamoto, F.-L. Hong, R. Higashi, and H. Katori, "An optical lattice clock," Nature 435, 321-324 (2005)
9. Masao Takamoto and Hidetoshi Katori, "Spectroscopy of the ¹S₀-³P₀ Clock Transition of ⁸⁷Sr in an Optical Lattice," Phys. Rev. Lett. 91, 223001 (2003)
10. Hidetoshi Katori, Masao Takamoto, V. G. Pal'chikov, and V. D. Ovsiannikov, "Ultrastable Optical Clock with Neutral Atoms in an Engineered Light Shift Trap," Phys. Rev. Lett. 91, 173005 (2003)