1. Home
  2. Research
  3. Centers & Labs
  4. RIKEN Center for Emergent Matter Science

RIKEN Center for Emergent Matter Science Electronic States Spectroscopy Research Team

Team Leader: Kyoko Ishizaka (Ph.D.)

Research Summary

Kyoko  Ishizaka(Ph.D.)

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


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

Selected Publications

Papers with an asterisk(*) are based on research conducted outside of RIKEN.

  • 1.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"
    Nat. Commun. 10, 1946 (2019).
  • 2.A. Nakamura, T. Shimojima, M. Matsuura, Y. Chiashi, M. Kamitani, H. Sakai, S. Ishiwata, H. Li, A. Oshiyama and K. Ishizaka.:
    "Evaluation of photo-induced shear strain in monoclinic VTe2 by ultrafast electron diffraction"
    Appl. Phys. Express 11, 092601 (2018).
  • 3.Shin-ichiro Ideta, Dongfang Zhang, Arend G. Dijkstra, Sergey Artyukhin, Sercan Keskin, Roberto Cingolani, Takahiro Shimojima, Kyoko Ishizaka, Hiroyuki Ishii, Kazutaka Kudo, Minoru Nohara and R. J. Dwayne Miller.:
    "Ultrafast dissolution and creation of bonds in IrTe2 induced by photodoping"
    Sci. Adv. 4, eaar3867 (2018).
  • 4.T. Sonobe, T. Shimojima, A. Nakamura, M. Nakajima, S.Uchida, K. Kihou, C.H. Lee, A. Iyo, H. Eisaki, K. Ohgushi, and K. Ishizaka.:
    "Orbital-anisotropic electronic structure in the nonmagnetic state of BaFe2(As1-xPx)2 superconductors"
    Sci. Rep. 8, 2169 (2018).
  • 5.T. Shimojima, W. Malaeb, A. Nakamura, T. Kondo, K. Kihou, C. H. Lee, A. Iyo, H. Eisaki, S. Ishida, M. Nakajima, S. Uchida, K. Ohgushi, K. Ishizaka, and S. Shin.:
    "Antiferroic electronic structure in the nonmagnetic superconducting state of the iron-based superconductors"
    Sci. Adv. 3, e1700466 (2017).
  • 6.M. Sakano,M. S. Bahramy, H. Tsuji, Araya, K. Ikeura, H. Sakai, S. Ishiwata, K. Yaji, K. Kuroda, A. Harasawa, S. Shin, and K. Ishizaka.:
    "Observation of spin-polarized bands and domain-dependent Fermi arcs in polar Weyl semimetal MoTe2"
    Phys. Rev. B 95, 121101(R) (2017).
  • 7.A. Nakamura, T. Shimojima, T. Sonobe, S. Yoshida, K. Ishizaka, W. Malaeb, S. Shin, S. Iimura, S. Matsuishi, and H. Hosono.:
    "Multiple-pseudogap phases in the hydrogen-doped LaFeAsO system"
    Phys. Rev. B 95, 064501 (2017).
  • 8.A. Nakamura, T. Shimojima, M. Nakano, Y. Iwasa, and K. Ishizaka.:
    "Electron and lattice dynamics of transition metal thin films observed by ultrafast electron diffraction and transient optical measurements"
    Struct, Dyn. 3, 064501 (2016).
  • 9.Y. Suzuki, T. Shimojima, T. Sonobe, A. Nakamura, M. Sakano, H. Tsuji, J. Omachi, K. Yoshioka, M. Kuwata-Gonokami, T. Watashige, R. Kobayashi, S. Kasahara, T. Shibauchi, Y. Matsuda, Y. Yamakawa, H. Kontani, and K. Ishizaka.:
    "Momentum-dependent sign inversion of orbital order in superconducting FeSe"
    Phys. Rev. B, 92, 205117 (2015).
  • 10.M. Sakano, K. Okawa, M. Kanou, H. Sanjo, T. Okuda, T. Sasagawa, and K. Ishizaka.:
    Topologically protected surface states in a centrosymmetric superconductor β-PdBi2"
    Nat. Commun., 6, 8595 (2015).

Recent Research Results

Related Links

Lab Members

Principal investigator

Kyoko Ishizaka
Team Leader

Core members

Takahiro Shimojima
Research Scientist
Asuka Nakamura
Special Postdoctoral Researcher

Contact Information

304-1, Frontier Research Laboratory
2-1 Hirosawa,
Wako, Saitama
351-0198, Japan
Tel: +81-(0)48-467-4492
Fax: +81-(0)48-462-1687
Email: kyoko.ishizaka [at] riken.jp