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RIKEN Center for Emergent Matter Science Topological Materials Design Research Unit

Unit Leader: Motoaki Hirayama (Ph.D.)

Research Summary

Motoaki Hirayama(Ph.D.)

English In our unit, we explore novel materials and their properties using first-principles calculations. In particular, we focus on the topological properties of the electronic band structure and search for topological materials with non-trivial properties. We investigate the properties and applications of these unique electronic states. We also include superconducting states and propose the emergence of Majorana fermions. In addition, we develop ab initio methods to treat correlation effects and design a wide range of materials. We design materials across a wide range of fields, including materials in the chemical and materials fields, such as electrides.

Main Research Fields

  • Interdisciplinary Science & Engineering

Related Research Fields

  • Engineering
  • Mathematical & Physical Sciences
  • Applied materials
  • Computational science
  • Thin film/Surface and interfacial physical properties


  • First-principles calculations
  • Theoretical materials design
  • Topological materials
  • Majorana fermions
  • Spin-orbit interaction

Selected Publications

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

  • 1. M. Hirayama, S. Matsuishi, H. Hosono, and S. Murakami.:
    "Higher-Order Topological Crystalline Insulating Phase and Quantized Hinge Charge in Topological Electride Apatite"
    Phys. Rev. Research 2, 043131 (2020).
  • 2. Y. Aihara*, M. Hirayama*, and S. Murakami.:
    "Anomalous dielectric response in insulators with the π Zak phase"
    Phys. Rev. Research 2, 033224 (2020).
  • 3. M. Hirayama, T. Tadano, Y. Nomura, and R. Arita.:
    "Materials design of dynamically stable d9 layered nickelates"
    Phys. Rev. B 101, 075107 (2020).
  • 4. M. Sakano, M. Hirayama, T. Takahashi, S. Akebi, M. Nakayama, K. Kuroda, K. Taguchi, T. Yoshikawa, K. Miyamoto, T. Okuda, K. Ono, H. Kumigashira, T. Ideue, Y. Iwasa, N. Mitsuishi, K. Ishizaka, S. Shin, T. Miyake, S. Murakami, T. Sasagawa, Takeshi Kondo.:
    "Radial spin texture in elemental tellurium with chiral crystal structure,"
    Phys. Rev. Lett. 124, 136404 (2020). (Editors' Suggestion)
  • 5. T. Ideue, M. Hirayama, H. Taiko, T. Takahashi, M. Murase, T. Miyake, S. Murakami, T. Sasagawa, and Y. Iwasa.:
    "Pressure-induced topological phase transition in noncentrosymmetric elemental Tellurium,"
    Proc Natl Acad Sci USA 1905524116 (2019).
  • 6. T. Inoshita,* M. Hirayama,* N. Hamada, H. Hosono, and S. Murakami.:
    "Topological semimetal phases manifested in transition-metal dichalcogenides intercalated with 3d metals"
    Phys. Rev. B. 100, 121112(R) (2019).
  • 7. M. Hirayama, T. Misawa, T. Ohgoe, Y. Yamaji, and M. Imada.:
    "Effective Hamiltonian for cuprate superconductors derived from multiscale ab initio scheme with level renormalization"
    Phys. Rev. B 99, 245155 (2019).
  • 8. M. Hirayama, S. Matsuishi, H. Hosono, and S. Murakami.:
    "Electrides as a New Platform of Topological Materials"
    Phys. Rev. X 8, 031067 (2018).
  • 9. *M. Hirayama, R. Okugawa, T. Miayake, and S. Murakami.:
    "Topological Dirac nodal lines and surface charges in fcc alkaline earth metals"
    Nat. Commun. 8, 14022 (2017).
  • 10. *M. Hirayama, S. Ishibashi, R. Okugawa, S. Murakami, and T. Miayake.:
    "Weyl Node and Spin Texture in Trigonal Tellurium and Selenium"
    Phys. Rev. Lett. 114, 206401 (2015).

Lab Members

Principal investigator

Motoaki Hirayama
Unit Leader

Contact Information

Main Research Bldg. 149
2-1, Hirosawa, Wako, Saitama 351-0198, Japan
Tel: +81-(0)48-426-1111 (ext. 3168)
Email: motoaki.hirayama [at] riken.jp