Akio Kawasaki
I am a senior research scientist at Time Standards Group, National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology. NMIJ is the metrology institute in Japan, and the group has an Yb optical lattice clock that is optimized for long-term continuous operation. I work on the spectroscopy of ytterbium towards fundamental physics searches.
Generally, my research interests lie in exploring fundamental physics with AMO techniques, or in more common words, precision measurements. In this field, researches are mainly performed as precision spectroscopies of atomic and molecular systems including ions. Although the energy scale of such spectroscopy is 1 eV, because its precision is extremely high, it can infer physics of billion times or even larger energy scale due to effects based on the uncertainty principle between time and energy. This opens a way to investigate high-energy particle physics through low-energy systems, and now spectroscopies are utilized for various searches oriented to fundamental physics, such as searches for time variation of fundamental constants, violations of parity, CPT, and Lorentz symmetries, EDMs of fundamental particles, dark matter, and gravitational waves.
Currently, I am performing precision spectroscopy of the 431 nm transition in Yb towards searches for time variation of the fine structure constant, ultralight dark matter, and new interactions between an electron and a neutron. I observed and performed an absolute frequency measurement of this transition for the first time in the world. The initial accuracy of the absolute frequency measurement is 8.2 kHz. With the isotope shift data obtained from absolute frequency measurements for multiple isotopes, we obtained the charge radius difference for ytterbium isotopes, and put constraints on the existence of the new interaction. We are targeting to narrow this down to <1 Hz level for the state-of-the-art precision spectroscopy and best performance on the searches for fundamental physics. See more in Current Research and an article for non-physicists.
A postdoc and a graduate student positions are available. Please contact Akio Kawasaki for details.
Latest update: 2024.4.2 Some conference presentations are added to Presentations.
Contact Information
Tsukuba Central 3
1-1-1 Umezono
Tsukuba-shi, Ibaraki 305-8563, Japan
E-mail address: akio．kawasaki＠aist．go．jp
Those who want to contact me via akiok@mit.edu and akiok@stanford.edu should contact the e-mail address above.
Last update: April 2, 2024