Research Topics

　Applying mechanical strain such as compression or tension can modify the magnetic properties of materials. Such strain-induced control of magnetism has attracted attention as a possible route toward low-power spintronic functionalities. In our group, we investigate the noncollinear antiferromagnet Mn₃Sn using first-principles calculations to understand how strain induces magnetization at the electronic-structure level. In particular, by combining real-space spin analysis with wave-number space (k-space) electronic structure analysis, we aim to clarify the microscopic origin of the piezomagnetic effect.

• Soichiro Kikuchi, Yuki Yanagi, Thi Ngoc Huyen Vu, Michi-To Suzuki, arXiv:2601.16634 (2026)
• Vu Thi Ngoc Huyen, Yuki Yanagi, Michi-To Suzuki, Phys. Rev. B 112, 104421/1-18 (2025)

　In layered materials such as MoS₂, the electronic and optical properties can change significantly depending on whether the material consists of a single layer or multiple stacked layers. We study the transition from a direct to an indirect band gap in MoS₂ as the number of layers increases, using Wannier-function-based analysis. By clarifying how interactions between electronic orbitals change through layer stacking, we aim to build a fundamental understanding of the electronic states of layered materials and their layer-dependent properties.

• Shunsuke Hirai, Ibuki Terada, Michi-To Suzuki, arXiv:2511.15178 (2025)

　Magnetic materials can exhibit the anomalous Hall effect, in which a voltage appears perpendicular to an applied electric field even without an external magnetic field. Recent studies have revealed that this phenomenon is closely related to the topology of electronic states and the quantum geometric properties of electronic wave functions. We investigate how special band degeneracies called nodal lines enhance anomalous and nonlinear Hall effects through the Berry curvature in the antiferromagnetic material NbMnP. By understanding the relationship between electronic structure and transport phenomena, we aim to clarify the origin of novel quantum transport phenomena.

• Ibuki Terada, Vu Thi Ngoc Huyen, Yuki Yanagi, Michi-To Suzuki, arXiv:2601.08317 (2026)
• Vu Thi Ngoc Huyen, Michi-To Suzuki, Kunihiko Yamauchi, and Tamio Oguchi
  , Phys. Rev. B 100, 094426/1-9 (2019)

  In addition to ferromagnetic materials, which have macroscopic magnetization and exhibit magnetic properties, there are various other types of magnetic materials, such as ferrimagnetism, chiral magnetism, and alternating magnetism, depending on the microscopic magnetization distribution inside the material, which cause various physical phenomena that differ from those of ferromagnetic materials. Under what conditions do these phenomena occur? How can we bring out more powerful phenomena? We investigate the properties of magnetic materials from various angles using theory and simulation, studying the relationship with functionality as a material and the possibility of new phenomena.

• Yuki Yanagi, Junya Ikeda, Kohei Fujiwara, Kentaro Nomura, Atsushi Tsukazaki, and Michi-To Suzuki, Phys. Rev. B 103, 205112/1-8 (2021)
• M.-T. Suzuki, T. Koretsune, M. Ochi, and R. Arita, Phys. Rev. B 95, 094406/1-11 (2017)

  Spin-orbit coupling, which is introduced into quantum mechanics as a relativistic correction for electron motion, causes a symmetry lowering in the electronic states of materials by coupling real space and spin space, which obey different symmetry rules, and is the origin of various physical phenomena. However, it is difficult to obtain a clear physical picture of the physical properties brought about by the coupling of spin, a resident of the quantum mechanical world, with real space, and in particular, the relationship with electric and magnetic ordering, including magnetism and superconductivity, is still a field of research where many mysteries remain. Our research group is studying the physical phenomena induced by spin-orbit coupling by making full use of mathematical science and first-principles calculations.

• Yuki Yanagi and Michi-To Suzuki, arXiv:2604.25539 (2026)

  The properties of a material are determined by the states of the electrons and atomic nuclei, which are its fundamental building blocks, within the material. Understanding the electronic state of material is essential to understanding the origin of macroscopic measurements such as electrical conduction, specific heat, and magnetization measurements, as well as experimental observations such as photoemission spectroscopy, nuclear magnetic resonance (NMR), and quantum osciration. The properties of electronic states can be investigated from many angles by analyzing band structures, density of states, Fermi surfaces, Berry phases, etc. Information on single-electron states obtained from first-principles calculations can also be used to calculate many physical quantities observed in experiments. Through collaborations with various experimental groups, our research group is working to understand unknown physical phenomena obtained experimentally.

• Hisashi Kotegawa, Akira Nakamura, Vu Thi Ngoc Huyen, Yuki Arai, Hideki Tou, Hitoshi Sugawara, Junichi Hayashi, Keiki Takeda, Chihiro Tabata, Koji Kaneko, Katsuaki Kodama, Michi-To Suzuki, Phys. Rev. B 110, 214417/1-8 (2024)
• Hisashi Kotegawa, Yoshiki Kuwata, Vu Thi Ngoc Huyen, Yuki Arai, Hideki Tou, Masaaki Matsuda, Keiki Takeda, Hitoshi Sugawara, Michi-To Suzuki, npj Quantum Mater. 8, 56/1-7 (2023)
• Michi-To SUZUKI and Hisatomo HARIMA, J. Phys. Soc. Jpn. 79 (2010) 024705/1-5.

  In many antiferromagnets, a highly symmetric magnetic structure is realized. In our research, we have shown that highly symmetric magnetic structures can be automatically generated for a given crystal structure by utilizing the multipole theory and group theory. We have shown that these theories can be combined with first-principles calculations to predict stable magnetic structures without the use of experimental information, and we are now working on the prediction of physical properties through simulations of magnetic structures. We are also engaged in research on physical properties using machine learning, a statistical analysis method that is the basis of artificial intelligence, and have proposed theoretical methods for converting magnetic structures into machine learning features.

• Takuya Nomoto, Susumu Minami, Yuki Yanagi, Michi-To Suzuki, Takashi Koretsune, and Ryotaro Arita, Phys. Rev. B 109, 094435/1-12 (2024)
• Michi-To Suzuki, Takuya Nomoto, Eiaki V. Morooka, Yuki Yanagi, and Hiroaki Kusunose, Phys. Rev. B 108, 014403/1-11 (2023)
• M.-T. Huebsch, T. Nomoto, M.-T. Suzuki, and R. Arita, Phys. Rev. X 11, 011031/1-25 (2021)

  Rare-earth and actinide compounds that contain f-electron systems are called heavy-electron systems. It is known that the prediction accuracy of electronic states by first-principles calculations is significantly reduced for the f-electron system. In addition, some heavy fermion systems form multipole orders by using large orbital degrees of freedom of f-electrons, and it is important to understand the electronic states under complex electric/magnetic order formation by first-principles calculations. Our research group is studying electronic states in strongly correlated electron systems through the development of first-principles calculation methods and analytical theory.

• Michi-To Suzuki, Hiroaki Ikeda, and Peter M. Oppeneer, J. Phys. Soc. Jpn. 87, 041008/1-24 (2018)
• M.-T. Suzuki, N. Magnani, and P. M. Oppeneer, Phys. Rev. B, 88,195146/1-14 (2013)
• Michi-To SUZUKI, Nicola Magnani, and Peter Oppeneer, Phys. Rev. B: Rapid Commun. 82 (2010) 241103/1-4.