Yasuyuki Kato's homepage

What's new

2024.11.05: I updated the list of preprint: S. Kasai et al. was newly uploaded.
2024.10.31: 新たに研究室配属を希望される学生さんへ[new!]のページを設けました．
2024.10.31: I updated the list of preprint: K. Shimizu et al. was newly uploaded.
2024.9.10: I updated the list of preprint: S.-S. Zhang et al. was newly uploaded.
2024.8.7: The list of publications was updated: K. Nakazawa et al. was newly published.
2024.7.26: The list of publications was updated: K. Fukui et al. was newly published.
2024.7.4: I updated the list of preprint: K. Shimizu et al. was newly uploaded.
2024.5.13: I updated the list of preprint: S. Ikegami et al. was newly uploaded.
2024.4.1: I have joined Department of Applied Physics, University of Fukui.
2024.3.13: I updated the list of preprint: K. Nakazawa et al. was newly uploaded.
2024.2.9: I updated the list of preprint: K. Fukui et al. was newly uploaded.
2024.2.6: I updated the list of publications: K. Nakazawa et al. was newly published.
2024.1.25: I updated the list of preprint: Y. Kato et al. was newly uploaded.
2023.11.2: I updated the list of publications: K. Shimizu et al. was newly published.
2023.8.30: I updated the list of publications: G. Sala et al. was newly published.
2023.8.24: I updated the list of publications: T. Nomura et al. was newly published.
2023.7.27: I updated the list of publications: S. Hayami and Y. Kato was newly published.
2023.7.20: I updated the list of preprint: K. Shimizu et al. was newly uploaded.
2023.6.13: I updated the list of publications: K. Fujiwara, Y. Kato et al. was published. This research is my first research result on amorphous materials. PRESS RELEASES (Japanese only) is available now.
2023.6.9: I updated the list of review articles and preprint. K. Shimizu et al. (Japanese) was newly published, and T. Nomura et al. was newly uploaded.
2023.5.27: I updated the list of publications: K. Fukui, Y. Kato, and Y. Motome was newly published.
2023.5.23: I updated the list of preprint: S. Hayami and Y. Kato was newly uploaded.
2023.3.31: I updated the list of publications: Y. Kato and Y. Motome was newly published.
2023.3.17: I updated the list of preprint: K. Fukui, Y. Kato, and Y. Motome was newly uploaded.
2023.2.22: I updated the list of publications: S. Hayami and Y. Kato. was published.
2022.12.20: I updated the list of preprint: K. Nakazawa, Y. Kato, and Y. Motome was newly uploaded.
2022.11.17: I updated the list of publications: K. Fukui et al. was published.
2022.10.31: I uploaded a new preprint (arXiv:2210.15816). We investigated temperature- and magnetic-field-induced topological transitions with changes in the density of the emergent magnetic monopoles and antimonopoles, and found that they are very often hidden.
2022.10.24: I updated the list of publications: M. Miura et al. was published. PRESS RELEASES (Japanese only) was also published.
2022.9.8: I updated the list of preprint: S. Hayami and Y. Kato was newly uploaded.
2022.8.4: I updated the list of publications: K. Fukui et al. and S. Okumura et al. were published.
2022.7.11: I updated the list of preprint: K. Fukui et al. was newly uploaded.
2022.6.14: I updated the list of publications: K. Shimizu et al. was published.
2022.6.7: I updated the list of publications: L. Testa et al. was published.
2022.5.13: I updated the list of publications: Y. Kato and Y. Motome. was published.
2022.4.30: I updated the list of publications: K. Nakazawa et al. was published.
2022.4.30: I updated Vita: A new project (URL) has been started.
2022.4.14: I updated the list of preprint: K. Fukui et al. was newly uploaded.
2022.3.22: I updated the list of publications. A couple of proceedings ( K. Shimizu et al. and S. Okumura et al.) were published.
2022.2.10: I uploaded a new preprint (arXiv:2202.04407). We found that the Pearson random walk (1905) is useful for this study (standing on the shoulders of giants).
2022.1.13: I updated the list of publications.
2022.1.11: I updated the list of publications.
2021.12.20: We published a new paper, "Nonreciprocal linear dichroism observed in electron spin resonance spectra of the magnetoelectric multiferroic Pb(TiO)Cu₄(PO₄)₄". publications are updated.
2021.12.07: We published a new paper about spin excitations in chiral magnetic metals. publications are updated.
2021.11.20: I updated the list of publications.
2021.10.1: I updated the list of preprint.
2021.9.14: I uploaded a new preprint (arXiv:2109.05628).
2021.8.22: Major update

Contact

Yasuyuki Kato (Associate Professor)

e-mail: katoyasu[at]u-fukui.ac.jp
Quantum Physics and Mathematical Sciences,
Department of Applied Physics,
University of Fukui,
Bunkyo 3-9-1, Fukui-shi, Fukui 910-8507, JAPAN

Vita

Education

Doctor's degree, University of Tokyo, Tokyo, Japan (March 24th, 2010) Thesis: Quantum Critical Phenomena of Bose-Hubbard Model in Three Dimensions.
Master's degree, University of Tokyo, Tokyo, Japan (March 22nd, 2007) Thesis: Simulations of Bose-Einstein Condensation with Quantum Monte-Carlo Method.
Bachelor's degree, Hokkaido University, Hokkaido, Japan (March 25th, 2005).

Experience

[April 2024-Current] Associate Professor, Department of Applied Physics, University of Fukui
[March 2023-March 2024] Lecturer in Motome Group, Department of Applied Physics, The University of Tokyo
[April 2015-February 2023] Research Associate in Motome Group, Department of Applied Physics, The University of Tokyo
[April 2014-March 2015] Special Postdoctoral Researcher at RIKEN Center for Emergent Matter Science (CEMS)
[April 2013-March 2014] Postdoctoral Fellow at RIKEN Center for Emergent Matter Science (CEMS)
[April 2010-March 2013] Postdoctoral Fellow at Los Alamos National Laboratory
[April 2008-March 2010] JSPS Research Fellowships for Young Scientists (DC2)
[June 2006-March 2008] ISSP Research Assistant

Awards

Los Alamos National Laboratory, "Postdoctoral Distinguished Performance Award (2012)", 2013.
International Institute for Complex Adaptive Matter (I2CAM), "ICAM-I2CAM Junior Scientist Exchange Awards", 2009.
International Institute for Complex Adaptive Matter (I2CAM), "ICAM-I2CAM Junior Scientist Exchange Awards", 2007.
北海道大学クラーク記念財団 “クラーク賞”, 2004.

Grants

Principal Investigator

Co-Investigator

Publications

Jump to Preprint, Published articles, Review articles, Proceedings.

ORCiD

Preprint

Shoya Kasai, Kotaro Shimizu, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Three-dimensional Topological Superstructure of Magnetic Hopfions Threaded by Meron Strings in Easy-plane Magnets arXiv:2411.00396.
Kotaro Shimizu, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Soliton penetration from edges in a monoaxial chiral magnet arXiv:2409.10842.
Shang-Shun Zhang, Yasuyuki Kato, E. A. Ghioldi, L. O. Manuel, A. E. Trumper, Cristian D. Batista, Large-N SU(4) Schwinger boson theory for coupled-dimer antiferromagnets arXiv:2409.04627.
Kotaro Shimizu, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Current-induced motion of nanoscale magnetic torons over the wide range of the Hall angle arXiv:2407.02983.
Sogen Ikegami, Kiyu Fukui, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Topological phase diagram of the Haldane model on a Bishamon-kikko—honeycomb lattice arXiv:2405.06287.
Yasuyuki Kato, Joji Nasu, Masahiro Sato, Tsuyoshi Okubo, Takahiro Misawa, and Yukitoshi Motome, Spin Seebeck Effect as a Probe for Majorana Fermions in Kitaev Spin Liquids, arXiv:2401.13175.
Y. Fujishiro, C. Terakura, A. Miyake, N. Kanazawa, K. Nakazawa, N. Ogawa, H. Kadobayashi, S. Kawaguchi, T. Kagayama, M. Tokunaga, Y. Kato, Y. Motome, K. Shimizu, and Y. Tokura, Anomalous charge transport upon quantum melting of chiral spin order, arXiv:2310.04823.

Published articles

Kazuki Nakazawa, Yasuyuki Kato, Yukitoshi Motome, Topological transitions by magnetization rotation in kagome monolayers of the ferromagnetic Weyl semimetal Co-based shandite, Phys. Rev. B 110, 085112 (2024). (arXiv:2402.16273)
Kiyu Fukui, Yasuyuki Kato, Yukitoshi Motome, Magnetic field effects on the Kitaev model coupled to environment, Phys. Rev. B 110, 024429 (2024). (arXiv:2402.05516)
Kazuki Nakazawa, Yasuyuki Kato, and Yukitoshi Motome, Magnetic, transport and topological properties of Co-based shandite thin films, Commun. Phys. 7, 48 (2024). (arXiv:2212.09026)
Kotaro Shimizu, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Emergent electric field from magnetic resonances in a one-dimensional chiral magnet, Phys. Rev. B 108, 134436 (2023). (arXiv:2307.08017)
Gabriele Sala, Matthew B. Stone, Gábor B. Halász, Mark D. Lumsden, Andrew F. May, Daniel M. Pajerowski, Seiko Ohira-Kawamura, Koji Kaneko, Daniel G. Mazzone, Gediminas Simutis, Jakob Lass, Yasuyuki Kato, Seung-Hwan Do, Jiao Y. Y. Lin, and Andrew D. Christianson, Field-tuned quantum renormalization of spin dynamics in the honeycomb lattice Heisenberg antiferromagnet YbCl₃, Commun. Phys. 6, 234 (2023).
Toshihiro Nomura, Yasuyuki Kato, Yukitoshi Motome, Atsushi Miyake, Masashi Tokunaga, Yoshimitsu Kohama, Sergei Zherlitsyn, Joachim Wosnitza, Shojiro Kimura, Tsukasa Katsuyoshi, Tsuyoshi Kimura, and Kenta Kimura, High-field phase diagram of the chiral-lattice antiferromagnet Sr(TiO)Cu₄(PO₄)₄, Phys. Rev. B 108, 054434 (2023). (arXiv:2306.02506)
Satoru Hayami and Yasuyuki Kato, Magnetic bubble crystal in tetragonal magnets, Phys. Rev. B 108, 024426 (2023). (arXiv:2305.08333)
Kohei Fujiwara, Yasuyuki Kato, Hitoshi Abe, Shun Noguchi, Junichi Shiogai, Yasuhiro Niwa, Hiroshi Kumigashira, Yukitoshi Motome, and Atsushi Tsukazaki, Berry curvature contributions of kagome-lattice fragments in amorphous Fe-Sn thin films, Nat. Commun. 14, 3399 (2023).
Kiyu Fukui, Yasuyuki Kato, and Yukitoshi Motome, Ground-State Phase Diagram of the Kitaev-Heisenberg Model on a Three-dimensional Hyperhoneycomb Lattice, J. Phys. Soc. Jpn. 92, 064708 (2023). (arXiv:2303.09156)
Yasuyuki Kato and Yukitoshi Motome, Hidden topological transitions in emergent magnetic monopole lattices, Phys. Rev. B 107, 094437 (2023). (arXiv:2210.15816)
Satoru Hayami and Yasuyuki Kato, Widely-sweeping magnetic field-temperature phase diagrams for skyrmion-hosting centrosymmetric tetragonal magnets, J. Magn. Magn. Mater. 571, 170547 (2023). (arXiv:2209.01810)
Kiyu Fukui, Yasuyuki Kato, Joji Nasu, and Yukitoshi Motome, Ground-state phase diagram of spin-S Kitaev-Heisenberg models, Phys. Rev. B 106, 174416 (2022). (arXiv:2207.03786)
Masashi Miura, Go Tsuchiya, Takumu Harada, Keita Sakuma, Hodaka Kurokawa, Naoto Sekiya, Yasuyuki Kato, Ryuji Yoshida, Takeharu Kato, Koichi Nakaoka, Teruo Izumi, Fuyuki Nabeshima, Atsutaka Maeda, Tatsumori Okada, Satoshi Awaji, Leonardo Civale, and Boris Maiorov, Thermodynamic approach for enhancing superconducting critical current performance, NPG Asia Mater 14, 85 (2022). (arXiv:2210.11688)
Shun Okumura, Satoru Hayami, Yasuyuki Kato, and Yukitoshi Motome, Magnetic Hedgehog Lattice in a Centrosymmetric Cubic Metal, J. Phys. Soc. Jpn. 91, 093702 (2022). (arXiv:2206.03042)
Kiyu Fukui, Yasuyuki Kato, Joji Nasu, and Yukitoshi Motome, Feasibility of Kitaev quantum spin liquids in ultracold polar molecules, Phys. Rev. B 106, 014419 (2022). (arXiv:2204.06144)
Kotaro Shimizu, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Phase degree of freedom and topology in multiple-Q spin textures, Phys. Rev. B 105, 224405 (2022). (arXiv:2201.03290)
Luc Testa, Peter Babkevich, Yasuyuki Kato, Kenta Kimura, Virgile Favre, Jose A. Rodriguez-Rivera, Jacques Ollivier, Stéphane Raymond, Tsuyoshi Kimura, Yukitoshi Motome, Bruce Normand, and Henrik M. Rønnow, Spin dynamics in the square-lattice cupola system Ba(TiO)Cu₄(PO₄)₄, Phys. Rev. B 105, 214406 (2022). [Editors’ Suggestion]
Yasuyuki Kato and Yukitoshi Motome, Magnetic field-temperature phase diagrams for multiple-Q magnetic ordering: Exact steepest descent approach to long-range interacting spin systems, Phys. Rev. B 105, 174413 (2022). (arXiv:2202.04407)
Kazuki Nakazawa, Yasuyuki Kato, and Yukitoshi Motome, Asymmetric modulation of Majorana excitation spectra and nonreciprocal thermal transport in the Kitaev spin liquid under a staggered magnetic field, Phys. Rev. B 105, 165152 (2022). (arXiv:2201.04274)
Mitsuru Akaki, Kenta Kimura, Yasuyuki Kato, Yuya Sawada, Yasuo Narumi, Hitoshi Ohta, Tsuyoshi Kimura, Yukitoshi Motome, and Masayuki Hagiwara, Nonreciprocal linear dichroism observed in electron spin resonance spectra of the magnetoelectric multiferroic Pb(TiO)Cu₄(PO₄)₄, Phys. Rev. Research 3, L042043 (2021).
Yasuyuki Kato, Satoru Hayami, and Yukitoshi Motome, Spin excitation spectra in helimagnetic states: Proper-screw, cycloid, vortex-crystal, and hedgehog lattices, Phys. Rev. B 104, 224405 (2021). (arXiv:2109.05628)
Koji Inui, Yasuyuki Kato, and Yukitoshi Motome, Determinant-free fermionic wave function using feed-forward neural networks, Phys. Rev. Research 3, 043126 (2021). (arXiv:2108.08631)
Shun Okumura, Takahiro Morimoto, Yasuyuki Kato, and Yukitoshi Motome, Quadratic optical responses in a chiral magnet, Phys. Rev. B 104, L180407 (2021), Phys. Rev. B 108, 219902(E) (2023) (erratum). (arXiv:2108.00674)
Kohei Fujiwara, Yasuyuki Kato, Takeshi Seki, Kentaro Nomura, Koki Takanashi, Yukitoshi Motome, and Atsushi Tsukazaki, Tuning scalar spin chirality in ultrathin films of the kagome-lattice ferromagnet Fe₃Sn, Commun. Mater. 2, 113 (2021).
Tsukasa Katsuyoshi, Kenta Kimura, Zhuo Yang, Yasuyuki Kato, Shojiro Kimura, Yukitoshi Motome, Yoshimitsu Kohama, and Tsuyoshi Kimura, Nonreciprocal Directional Dichroism in a Magnetic-Field-Induced Ferroelectric Phase of Pb(TiO)Cu₄(PO₄)₄, J. Phys. Soc. Jpn. 90, 123701 (2021). [Editors’ Choice]
Petr A. Mishchenko, Yasuyuki Kato, and Yukitoshi Motome, Quantum Monte Carlo method on asymptotic Lefschetz thimbles for quantum spin systems: An application to the Kitaev model in a magnetic field, Phys. Rev. D 104, 074517 (2021). (arXiv:2106.07937)
Seong-Hoon Jang, Yasuyuki Kato, and Yukitoshi Motome, Vortex creation and control in the Kitaev spin liquid by local bond modulations, Phys. Rev. B 104, 085142 (2021). (arXiv: 2105.14562)
Kenta Kimura, Yasuyuki Kato, Shojiro Kimura, Yukitoshi Motome, and Tsuyoshi Kimura, Crystal-chirality-dependent control of magnetic domains in a time-reversal-broken antiferromagnet, npj Quantum Mater. 6, 54 (2021).
Kotaro Shimizu, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Spin Moiré Engineering of Emergent Electromagnetism, Phys. Rev. B 103, 184421 (2021). (arXiv:2009.14569)
Haruki Watanabe, Yasuyuki Kato, Hoi Chun Po, and Yukitoshi Motome, Fractional corner magnetization of collinear antiferromagnets, Phys. Rev. B 103, 134430 (2021). (arXiv:2101.05058)
Kotaro Shimizu, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Phase transitions between helices, vortices, and hedgehogs driven by spatial anisotropy in chiral magnets, Phys. Rev. B 103, 054427 (2021). (arXiv:2010.16187)
Tatsuki Sato, Yuma Umimoto, Yusuke Sugita, Yasuyuki Kato, and Yukitoshi Motome, Optical Hall response in spin-orbit coupled metals: Comparative study of magnetic cluster monopole, quadrupole, and toroidal orders, Phys. Rev. B 103, 054416 (2021). (arXiv:2011.06267)
Seong-Hoon Jang, Ryoya Sano, Yasuyuki Kato, and Yukitoshi Motome, Computational design of f-electron Kitaev magnets: honeycomb and hyperhoneycomb compounds A₂PrO₃ (A= alkali metals), Phys. Rev. Materials 4, 104420 (2020). (arXiv:1912.03422)
Tim Eschmann, Petr A. Mishchenko, Kevin O'Brien, Troels A. Bojesen, Yasuyuki Kato, Maria Hermanns, Yukitoshi Motome, and Simon Trebst, Thermodynamic classification of three-dimensional Kitaev spin liquids, Phys. Rev. B 102, 075125 (2020). (arXiv:2006.07386)
Yasuyuki Kato, Shang-Shun Zhang, Yusuke Nishida, and C. D. Batista, Magnetic-field-induced tunability of spin Hamiltonians: Resonances and Efimov states in Yb₂Ti₂O₇, Phys. Rev. Research 2, 033024 (2020). (arXiv:2003.06738)
Shun Okumura, Satoru Hayami, Yasuyuki Kato, and Yukitoshi Motome, Magnetic Hedgehog Lattices in Noncentrosymmetric Metals, Phys. Rev. B 101, 144416 (2020). (arXiv:1908.05044)
Yusuke Sugita, Yasuyuki Kato, and Yukitoshi Motome, Antiferromagnetic Kitaev Interactions in Polar Spin-Orbit Mott Insulators, Phys. Rev. B 101, 100410(R) (2020). (arXiv:1905.12139)
Junki Yoshitake, Joji Nasu, Yasuyuki Kato, and Yukitoshi Motome, Majorana-Magnon Crossover by a Magnetic Field in the Kitaev Model: Continuous-Time Quantum Monte Carlo Study, Phys. Rev. B 101, 100408(R) (2020). (arXiv:1907.07299)
Petr A. Mishchenko, Yasuyuki Kato, Kevin O'Brien, Troels A. Bojesen, Tim Eschmann, Maria Hermanns, Simon Trebst, and Yukitoshi Motome, Chiral spin liquids with crystalline ℤ₂ gauge order in a three-dimensional Kitaev model, Phys. Rev. B 101, 045118 (2020). [Editors’ Suggestion] (arXiv:1907.10241)
T. Eschmann, P. A. Mishchenko, T. A. Bojesen, Y. Kato, M. Hermanns, Y. Motome, and S. Trebst, Thermodynamics of a gauge-frustrated Kitaev spin liquid, Phys. Rev. Research 1, 032011(R) (2019). (arXiv:1901.05283)
Yasuyuki Kato and Hiroaki Ishizuka, Colossal enhancement of spin-chirality-related Hall effect by thermal fluctuation, Phys. Rev. Applied 12, 021001 (2019). [Letter] (arXiv:1812.09805)
Shun Okumura, Hiroaki Ishizuka, Yasuyuki Kato, Jun-ichiro Ohe, and Yukitoshi Motome, Spin-current diode with a monoaxial chiral magnet, Appl. Phys. Lett. 115, 012401 (2019). (arXiv:1903.12358)
Seong-Hoon Jang, Ryoya Sano, Yasuyuki Kato, and Yukitoshi Motome, Antiferromagnetic Kitaev interaction in f-electron based honeycomb magnets, Phys. Rev. B 99, 241106(R) (2019). (arXiv:1807.01443)
Ken N. Okada, Yasuyuki Kato, and Yukitoshi Motome, Magnetoelectric effect in band insulator–ferromagnet heterostructures, Phys. Rev. B 99, 134442 (2019). (arXiv:1902.04204)
Yasuyuki Kato, Kenta Kimura, Atsushi Miyake, Masashi Tokunaga, Akira Matsuo, Koichi Kindo, Mitsuru Akaki, Masayuki Hagiwara, Shojiro Kimura, Tsuyoshi Kimura, Yukitoshi Motome, Magnetoelectric behavior from cluster multipoles in square cupolas: Study of Sr(TiO)Cu₄(PO₄)₄ in comparison with Ba and Pb isostructurals, Phys. Rev. B 99, 024415 (2019). (arXiv:1810.11929)
Ken N. Okada, Yasuyuki Kato, Yukitoshi Motome, Multiple-Q magnetic orders in Rashba-Dresselhaus metals, Phys. Rev. B 98, 224406 (2018). (arXiv:1809.07582)
Kenta Kimura, Yasuyuki Kato, Kunihiko Yamauchi, Atsushi Miyake, Masashi Tokunaga, Akira Matsuo, Koichi Kindo, Mitsuru Akaki, Masayuki Hagiwara, Shojiro Kimura, Masayuki Toyoda, Yukitoshi Motome, and Tsuyoshi Kimura, Magnetic structural unit with convex geometry: A building block hosting an exchange-striction-driven magnetoelectric coupling, Phys. Rev. Materials 2, 104415 (2018). [Editors’ Suggestion] (arXiv:1807.10457)
Joji Nasu, Yasuyuki Kato, Yoshitomo Kamiya, and Yukitoshi Motome, Successive Majorana Topological Transitions Driven by a Magnetic Field in the Kitaev Model, Phys. Rev. B 98, 060416(R) (2018). (arXiv:1805.02423)
Yoshifumi Tokiwa, Takuya Yamashita, Daiki Terazawa, Kenta Kimura, Yuichi Kasahara, Takafumi Onishi, Yasuyuki Kato, Mario Halim, Philipp Gegenwart, Takasada Shibauchi, Satoru Nakatsuji, Eun-Gook Moon, and Yuji Matsuda, Discovery of Emergent Photon and Monopoles in a Quantum Spin Liquid, J. Phys. Soc. Jpn. 87, 064702 (2018). (arXiv:1803.05557)
Shun Okumura, Yasuyuki Kato, and Y. Motome, Lock-in of a Chiral Soliton Lattice by Itinerant Electrons, J. Phys. Soc. Jpn. 87, 033708 (2018). (arXiv:1801.02872)
Rina Takashima, Yasuyuki Kato, Youichi Yanase, and Yukitoshi Motome, Generation and control of noncollinear magnetism by supercurrent, Phys. Rev. B 97, 081107(R) (2018). (arXiv:1710.11349)
Ryoya Sano, Yasuyuki Kato, and Yukitoshi Motome, Kitaev-Heisenberg Hamiltonian for High-Spin d₇ Mott Insulators, Phys. Rev. B 97, 014408 (2018). (arXiv:1710.11357)
Taichi Kosugi, Hirofumi Nishi, Yasuyuki Kato, and Yu-ichiro Matsushita, Periodicity-free unfolding method of electronic energy spectra, J. Phys. Soc. Jpn. 86, 124717 (2017). (arXiv:1707.03116)
Yasuyuki Kato, Yoshitomo Kamiya, Joji Nasu, and Yukitoshi Motome, Chiral Spin Liquids at Finite Temperature in a Three-Dimensional Kitaev Model, Phys. Rev. B 96, 174409 (2017), Phys. Rev. B 97, 139902(E) (2018) (erratum). (arXiv:1707.02794)
Petr A. Mishchenko, Yasuyuki Kato, and Yukitoshi Motome, Finite-temperature phase transition to the Kitaev spin liquid on a hyperoctagon lattice: a large-scale quantum Monte Carlo study, Phys. Rev. B 96, 125124 (2017), Phys. Rev. B 97, 079905(E) (2018) (erratum). (arXiv:1706.05057)
Junki Yoshitake, Joji Nasu, Yasuyuki Kato, and Yukitoshi Motome, Majorana dynamical mean-field study of spin dynamics at finite temperatures in the honeycomb Kitaev model, Phys. Rev. B 96, 024438 (2017). (arXiv:1704.02707)
L. Wang, N. Chepiga, D.-K. Ki, L. Li, F. Li, W. Zhu, Y. Kato, O.S. Ovchinnikova, F. Mila, I. Martin, D. Mandrus, and A. F. Morpurgo, Controlling the topological sector of magnetic solitons in exfoliated Cr_1/3NbS₂ crystals, Phys. Rev. Lett. 118, 257203(2017). (arXiv:1704.02773)
Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Monte Carlo Study of Magnetoresistance in a Chiral Soliton Lattice, J. Phys. Soc. Jpn. 86, 063701 (2017). (arXiv:1704.01708)
D. Wulferding, H. Kim, I. Yang, J. Jeong, K. Barros, Y. Kato, I. Martin, O. E. Ayala-Valenzuela, M. Lee, H. C. Choi, F. Ronning, L. Civale, R. E. Baumbach, E. D. Bauer, J. D. Thompson, R. Movshovich, and Jeehoon Kim, Domain engineering of the metastable domains in the 4f-uniaxial-ferromagnet CeRu₂Ga₂B, Sci. Rep. 7, 46296 (2017).
Joji Nasu, Yasuyuki Kato, Junki Yoshitake, Yoshitomo Kamiya, and Yukitoshi Motome, Spin-Liquid-to-Spin-Liquid Transition in Kitaev Magnets Driven by Spin Fractionalization, Phys. Rev. Lett. 118, 137203 (2017). (arXiv:1610.07343)
Yasuyuki Kato, Kenta Kimura, Atsushi Miyake, Masashi Tokunaga, Akira Matsuo, Koichi Kindo, Mitsuru Akaki, Masayuki Hagiwara, Masakazu Sera, Tsuyoshi Kimura, and Yukitoshi Motome, Magnetoelectric Behavior from S = 1/2 Asymmetric Square Cupolas, Phys. Rev. Lett. 118, 107601 (2017). (arXiv:1611.00086)
H. Takatsu, S. Kittaka, A. Kasahara, Y. Kono, T. Sakakibara, Y. Kato, S. Onoda, B. Fak, J. Ollivier, J. W. Lynn, T. Taniguchi, M. Wakita, and H. Kadowaki, Quadrupole Order in the Frustrated Pyrochlore Tb_2+xTi_2-xO_7+y, Phys. Rev. Lett. 116, 217201(2016). (arXiv:1506.04545)
Yasuyuki Kato and Takahiro Misawa, Quantum Triciriticality in Antiferromagnetic Ising Model with Transverse Field: A Quantum Monte-Carlo Study, Phys. Rev. B 92, 174419 (2015)., Phys. Rev. B 107, 059903(E) (2023) (erratum). (arXiv:1507.08741)
Yoshitomo Kamiya, Yasuyuki Kato, Joji Nasu, and Yukitoshi Motome, Magnetic Three States of Matter: A Quantum Monte Carlo study of Spin Liquids, Phys. Rev. B 92, 100403(R) (2015), Phys. Rev. B 93, 179902(E) (2016) (erratum). (arXiv:1504.06911)
Yasuyuki Kato and Shigeki Onoda, Numerical evidence of quantum melting of spin ice: quantum-classical crossover, Phys. Rev. Lett. 115, 077202 (2015). (arXiv:1411.1918)
Ippei Danshita, Daisuke Yamamoto, and Yasuyuki Kato, Cubic-quintic nonlinearity in superfluid Bose-Bose mixtures in optical lattices: Heavy solitary waves, barrier-induced criticality, and current-phase relations, Phys. Rev. A 91, 013630 (2015)., Phys. Rev. A 104, 049902(E) (2021) (erratum). (arXiv:1409.7185)
Rodrigo A. Muniz, Yasuyuki Kato, and Cristian D. Batista, Generalized spin-wave theory: Application to the bilinear-biquadratic model, PTEP 083I01 (2014). (arXiv:1307.7731)
Yasuyuki Kato, Daisuke Yamamoto, and Ippei Danshita, Quantum Tricriticality at the Superfluid-Insulator Transition of Binary Bose Mixtures, Phys. Rev. Lett. 112, 055301 (2014). (arXiv:1311.2145)
Kipton Barros and Yasuyuki Kato, Efficient Langevin simulation of coupled classical fields and fermions, Phys. Rev. B 88, 235101 (2013). (arXiv:1303.1101)
Zhifeng Zhang, Keola Wierschem, Ian Yap, Yasuyuki Kato, Cristian D. Batista, and Pinaki Sengupta, Phase diagram and magnetic excitations of anisotropic spin-one magnets, Phys. Rev. B 87, 174405 (2013). (arXiv:1301.2025)
Yasuyuki Kato, Multidiscontinuity algorithm for world-line Monte Carlo simulations, Phys. Rev. E 87, 013310 (2013). (arXiv:1211.1627)
Yusuke Nishida, Yasuyuki Kato, and Cristian D. Batista, Efimov effect in quantum magnets, Nat. Phys. 9, 93 (2013). (arXiv:1208.6214)
A. P. Petrovic, Y. Kato, S.S. Sunku, T. Ito, P. Sengupta, L. Spalek, M. Shimuta, T. Katsufuji, C.D. Batista, S. Saxena, and C. Panagopoulos, Intrinsic Structural Disorder and the Magnetic Ground State in Bulk EuTiO₃, Phys. Rev. B 87, 064103 (2013). (arXiv:1204.0150)
E. Duchon, Y. Kato, and N. Trivedi, Diagnostic for phases and quantum critical regions using deviations from the local fluctuation-disipation theorem, Phys. Rev. A 86, 063608 (2012). (arXiv:1112.0592)
Keola Wierschem, Yasuyuki Kato, Yusuke Nishida, Cristian D. Batista, and Pinaki Sengupta, Magnetic and nematic orderings in spin-1 antiferromagnets with single-ion anisotropy, Phys. Rev. B 86, 201108 (2012). (arXiv:1209.0688)
Yasuyuki Kato, C.D. Batista, and I. Vekhter, Structure of magnetic order in Pauli limited unconventional superconductors, Phys. Rev. B 86, 174517 (2012). (arXiv:1209.0834)
B. G. Ueland, C. F. Miclea, Yasuyuki Kato, O. Ayala-Valenzuela, R. D. McDonald, R. Okazaki, P. H. Tobosh, M. A. Torrez, F. Ronning, R. Movshovich, Z. Fisk, E. D. Bauer, Ivar Martin, and J. D. Tompson, Controllable chirality-induced geometrical Hall effect in a frustrated highly correlated metal, Nat. Commun. 3, 1067 (2012). (arXiv:1209.6024)
Christine Kuntscher, Kaneez Rabia, M.K. Forthaus, M.M. Abd-Elmeguid, F. Rivadulla, Y. Kato, and C. D. Batista, Nonmonotonic evolution of the charge gap in ZnV₂O₄ under pressure, Phys. Rev. B 86, 020405(R) (2012).
Yasuyuki Kato, Gia-Wei Chern, K.A. Al-Hassanich, Natalia Perkins, and C.D. Batista, Orbital Disorder Induced by Charge Fluctuation in Vanadium Spinels, Phys. Rev. Lett. 108, 247215 (2012). (arXiv:1205.1081)
Toshihiro Sato, Yasuyuki Kato, Takafumi Suzuki, and Naoki Kawashima, Validity of projected Gross-Pitaevskii simulation: Comparison with quantum Monte Carlo, Phys. Rev. E 85, 050105(R) (2012).
Yasuyuki Kato, K.A. Al-Hassanieh, A.E. Feiguin, Eddy Thimmermans, and C.D. Batista, Novel Polaron State for single impurity in a bosonic Mott insulator, EPL 98, 46003 (2012). (arXiv:1110.6466)
K. W. Mahmud, E.N. Duchon, Y. Kato, N. Kawashima, R.T. Scalettar, and N. Trivedi, Finite-temperature study of bosons in a two-dimensional optical lattice, Phys. Rev. B 84, 054302 (2011). (arXiv:1101.5726)
Yasuyuki Kato, C.D. Batista, and I. Vekhter, Antiferromagnetic Order in Pauli Limited Unconventional Superconductors, Phys. Rev. Lett. 107, 096401 (2011). (arXiv:1104.0391)
Yasuyuki Kato, Ivar Martin, and C. D. Batista, Stability of the Spontaneous Quantum Hall State in the Triangular Kondo-Lattice Model, Phys. Rev. Lett. 105, 266405 (2010). (arXiv:1009.3059)
Yasuyuki Kato and Naoki Kawashima, Finite-Size Scaling for Quantum Criticality above the Upper Critical Dimension: Superfluid-Mott-Insulator Transition in Three Dimensions, Phys. Rev. E 81, 011123 (2010). (arXiv:0910.0082)
Qi Zhou, Yasuyuki Kato, Naoki Kawashima, and Nandini Trivedi, Direct Mapping of the Finite Temperature Phase Diagram of Strongly Correlated Quantum Models, Phys. Rev. Lett. 103, 085701 (2009), Phys. Rev. Lett. 105, 199602 (2010). (reply) (arXiv:0901.0606)
Jim. K. Freericks, Hulikal. R. Krishnamurthy, Yasuyuki Kato, Naoki Kawashima, and Nandini Trivedi, Strong-coupling expansion for the momentum distribution of the Bose-Hubbard model with benchmarking against exact numerical results, Phys. Rev. A 79, 053631 (2009), Phys. Rev. A 85, 019913(E) (2012) (erratum). (arXiv:0902.3435)
Yasuyuki Kato and Naoki Kawashima, Quantum Monte Carlo method for the Bose-Hubbard model with harmonic confining potential, Phys. Rev. E 79, 021104 (2009).
Yasuyuki Kato, Qi Zhou, Naoki Kawashima, and Nandini Trivedi, Sharp peaks in the momentum distribution of bosons in optical lattices in the normal state, Nat. Phys. 4, 617(2008).
Yasuyuki Kato, Takafumi Suzuki, and Naoki Kawashima, Modification of Directed-Loop Algorithm for Continuous Space Simulation of Bosonic Systems, Phys. Rev. E 75, 066703 (2007).

Review articles

清水宏太郎, 奥村駿, 加藤康之, 求幸年, 【最近の研究から】トポロジカル磁気構造におけるスピンモアレエンジニアリング, 日本物理学会誌，78，pp.314-319 (2023). [表紙絵掲載]
Y. Motome, R. Sano, S.-H. Jang, Y. Sugita, and Y. Kato, Materials design of Kitaev spin liquids beyond the Jackeli-Khaliullin mechanism, J. Phys.: Condens. Matter 32, 404001 (2020). (arXiv:2001.03731)
加藤康之，木村健太, 【最近の研究から】正四角台塔をユニットに持つ反強磁性体が示す電気磁気効果, 日本物理学会誌，73，pp.715-719 (2018).

Proceedings

Kotaro Shimizu, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Phase shift, ellipticity, angle, and topological number in skyrmion lattices, J. Phys.: Conf. Ser. 2164, 012069 (2022). (arXiv:2109.14222)
Shun Okumura, Takahiro Morimoto, Yasuyuki Kato, and Yukitoshi Motome, Electrical conductivity in helical and conical magnetic states, J. Phys.: Conf. Ser. 2164, 012068 (2022). (arXiv:2109.15038)
Shun Okumura, Satoru Hayami, Yasuyuki Kato, and Yukitoshi Motome, Tracing Monopoles and Anti-monopoles in a Magnetic Hedgehog Lattice, JPS Conf. Proc. 30, 011010 (2020). (arXiv:1909.01316)
Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, Chiral helimagnetic state in a Kondo lattice model with the Dzyaloshinskii-Moriya interaction, Physica B 536, 223-225 (2018). (arXiv:1707.00397)
Yasuyuki Kato, Yoshitomo Kamiya, Joji Nasu, and Yukitoshi Motome, Global constraints on ℤ₂ fluxes in two different anisotropic limits of a hypernonagon Kitaev model, Physica B 536, 405-407 (2018). (arXiv:1805.07115)
Ryo Ozawa, Yasuyuki Kato, and Yukitoshi Motome, Simulated floating zone method, J. Phys.: Conf. Ser. 807, 102005 (2017). (arXiv:1609.07191)
Yasuyuki Kato, Quantum Monte-Carlo study of magnetic ordering in ZnV₂O₄, Physics Procedia 34, 60 (2012). (arXiv:1202.5366)
Naoki Kawashima and Yasuyuki Kato, Monte Carlo approach to phase transitions in quantum systems, J. Phys.: Conf. Ser. 143, 012012 (2009).

Research interests

Monte-Carlo simulations for quantum and classical systems
Ultracold atomic gases
Magnetism in itinerant electron systems
Superconductivity
Quantum magnets
Magnetoelectric effects

I have studied different strongly correlated problems in condensed matter physics. In general, I’m interested in the search for new states of matter, anomalous responses in them, and in the general area of phase transitions and critical phenomena that arise from micro-scale many body interactions. This area covers a very large spectrum of physical systems that includes cooperative phenomena in ultracold atomic gases, exotic magnetic orderings in magnetic metals where itinerant electrons and localized magnetic moments are correlated each other, spin and orbital orderings in transition metal oxides, magnetic field induced coexistence of magnetism and superconductivity, quantum magnetism in frustrated Mott insulators, magnetoelectric effect in antiferromagnets, and chiral spin liquid transition in three dimension. In general, I approached these problems by combining numerical techniques, such as quantum and classical Monte-Carlo methods, with the analytical methods that were appropriate for each specific problem.

研究室配属を希望される学生さんへ

当研究室は2024年4月にできたばかりの新しい研究室で，2025年度配属された方は初代となります．大学院進学も検討してもらえるとうれしいです．

研究内容

当研究室では量子力学・統計力学に基づいた物性物理学の理論的研究を行っています． 強相関量子系と呼ばれる，原子や電子など量子力学的に振る舞うミクロな要素が膨大な数集まり相互作用している系にみられる特異な現象を対象に研究を進めています．特に「相転移と臨界現象」，「量子」，「トポロジー」を軸に統計基礎論の量子多体問題から具体的な磁性体が示す応答現象までを幅広く対象にしています．（これまで習った通り）相互作用自体は、ほとんどの場合単純な数式で表されますが，それに起因するマクロな現象は驚くほど多彩です（図）．冷却原子気体や量子磁性体の量子臨界現象（超流動ー絶縁体転移などの絶対零度の相転移現象），量子スピン液体（絶対零度まで秩序化しない磁性体），カイラル磁性体やアモルファスの異常ホール効果（ゼロ磁場のホール効果），電気磁気効果（電場で磁石をコントロール），磁性体中のエフィモフ効果（量子力学的効果によって形成される３体の束縛状態）など，さまざまな現象の発現の仕組みの解明や実証実験の提案を目指してみませんか？

具体的な研究のアプローチ法は，物理現象の普遍的なしくみの理解を主目的とした，本質を抽出したシンプルな模型構築と 数値計算による精密な模型解析によるものです．先に述べたとおり，模型自体は比較的単純な数式で表されます．しかし，そこには多体問題が内在しているため厳密で解析的な解を得られることは稀です．そこで，コンピュータを駆使した計算が重要な役割を果たせる訳です．日進月歩の数値計算アルゴリズムの開発が行われています．私も最先端の数値計算アルゴリズムの利用や開発に積極的に取り組んでおります．配属された学生さんは，研究を通じて汎用性のあるデータ解析やプログラミングの能力を高めることができることと思います．学生さんとは円滑なコミュニケーションをとりながら懇切丁寧な指導を行っていきますので，安心して配属を検討してもらえればと思います．私と一緒に研究の楽しさを味わってみませんか？

向いていると思われる学生さん

量子力学と統計力学が両方好き．
パソコンが好き．
自分の手計算が信用できない．
ひとつひとつ手作業するのが苦手で，プログラムで自動処理したい．
エクセルのオートフィルが好き．

配属を迷われている学生さんの研究室訪問は大歓迎です．お気軽にお問い合わせください．