RIKEN Center for Emergent Matter Science Electronic States Spectroscopy Research Team

Team Director: Kyoko Ishizaka (Ph.D.)

Japanese Page

Research Summary

We investigate spin, electron, and crystal structures of materials showing a variety of physical properties, functions, and quantum phenomena. We use spin- and angle-resolved photoemission spectroscopy, which can probe the energy, momentum, and spin of electrons in solids, to study new materials and phenomena such as superconductors, thermoelectric / spintronic materials, topological quantum states, and many-body effects in strongly correlated systems. We are also starting a project on the ultrafast time-resolved transmission electron microscope utilizing pulsed lasers. Dynamics of spin, electron, and crystal structures in nanometer and femto-nanosecond scales will be explored.

Main Research Fields

Mathematical & Physical Sciences

Related Research Fields

Interdisciplinary Science & Engineering

Keywords

Photoemission Spectroscopy
Ultrafast TEM
Nano-scale magnetism
Superconductivity
Strongly correlated system

Selected Publications

1. T. Shiratori, J. Koga, T. Shimojima, K. Ishizaka, and A. Nakamura,
"Development of ultrafast four-dimensional precession electron diffraction"
Ultramicroscopy, 267 114064 (2024).
2. S. Akatsuka, M. Sakano, K. Ishizaka et al.,
"180 °-twisted bilayer ReSe₂ as an artificial noncentrosymmetric semiconductor"
Phys.Rev.Research.6, L022048 (2024).
3. T. Shimojima, A. Nakamura, K. Ishizaka,
"Development and applications of ultrafast transmission electron microscopy",
Microscopy dfad021 (2023).
4. Asuka Nakamura, Takahiro Shimojima, and Kyoko Ishizaka.:
"Characterizing an Optically Induced Sub-micrometer Gigahertz Acoustic Wave in a Silicon Thin Plate"
Nano Lett. 23, 2490–2495 (2023).
5. B. Saika, R. Arita, Y. Iwasa, M. Nakano, K. Ishizaka et al.,
"Signature of topological band crossing in ferromagnetic Cr_1/3NbSe₂ epitaxial thin film"
Phys. Rev. Research 4, L042021 (2022).
6. M. Sakano, Y. Tanaka, S. Masubuchi, S. Okazaki, T. Nomoto, A. Oshima, K. Watanabe, T. Taniguchi, R. Arita, T. Sasagawa, T. Machida, and K. Ishizaka,
"Odd-even layer-number effect of valence-band spin splitting in WTe₂",
Phys. Rev. Research 4, 0232477 (2022).
7. T. Shimojima, A. Nakamura, X. Z. Yu, K. Karube, Y. Taguchi, Y. Tokura, and K. Ishizaka.:
"Nano-to-micro spatiotemporal imaging of magnetic skyrmion’s life cycle"
Sci. Adv. 7, eabg1322/1-8(2021).
8. A. Nakamura, T. Shimojima, Y. Chiashi, M. Kamitani, H. Sakai, S. Ishiwata, H. Li, and K. Ishizaka.:
"Nanoscale Imaging of Unusual Photoacoustic Waves in Thin Flake VTe₂"
Nano Lett. 20, 7, 4932 (2020).
9. N. Mitsuishi, K. Ishizaka et al.:
"Switching of band inversion and topological surface states by charge density wave"
Nature Commun. 11, 2466 (2020).
10. T. Shimojima, Y. Suzuki, A. Nakamura, N. Mitsuishi, S. Kasahara, T. Shibauchi, Y. Matsuda, Y. Ishida, S. Shin and K. Ishizaka.:
"Ultrafast nematic-orbital excitation in FeSe"
Nature Commun. 10, 1946 (2019).