Talks

Conferences and Workshops

International

1. [upcoming] Kiyu Fukui, "Numerical study on novel Kitaev materials for quantum spin liquid states with exotic fractional excitations", 86, 17th symposium on Discovery, Fusion, Creation of New Knowledge by Multidisciplinary Computational Sciences [Oct. 6 - 7, 2025 (Tsukuba, Japan)].

2. Kiyu Fukui and Yukitoshi Motome, "Unveiling new magnetic phases in 3D extended Kitaev models", 12PS7.5.3 [Aug. 12] (oral talk), 30th International Conference on LOW TEMPERATURE PHYSICS [Aug. 7 - 13, 2025 (Bilbao, Spain)].

3. ○Sogen Ikegami, Kiyu Fukui, Rico Pohle, and Yukitoshi Motome, "Multipole orders and quantum spin liquids in spin-3/2 honeycomb models", poster, Joint ICTP-WE Heraeus School and Workshop on Advances in Quantum Matter: Pushing the Boundaries (smr 4094) [Aug. 4 - 15, 2025 (Trieste, Italy)].

4. Kiyu Fukui and Yukitoshi Motome, "Unveiling new magnetic phases in an extended Kitaev model on a 3D hyperhoneycomb lattice", 31 [Jul. 7] (poster), International Conference on Strongly Correlated Electron Systems 2025 (SCES2025) [Jul. 6 - 11, 2025 (Montréal, Canada)].

5. Kiyu Fukui, Yasuyuki Kato, and Yukitoshi Motome, "Kitaev spin liquid coupled to environment", Nov. 19 (oral talk), ISSP Theory mini-Workshop Correlated Quantum Materials + beyond (CQM+b2024) [Nov. 18 - 29, 2024 (Kashiwa, Japan)].

6. Kiyu Fukui, "Effect of a magnetic field on the Kitaev model coupled to environment", 67 (poster), 16th Symposium on Discovery, Fusion, Creation of New Knowledge by Multidisciplinary Computational Sciences [Oct. 7 - 8, 2024 (Tsukuba, Japan)].

7. Kiyu Fukui and Yukitoshi Motome, "Topological Majorana flat bands in the Kitaev model on a Bishamon-kikko lattice", Aug. 8 (oral talk), New Frontiers in Advanced Magnetism (NFAM) [Aug. 5 - 9, 2024 (Sapporo, Japan)].

8. Kiyu Fukui and Yukitoshi Motome, "Topological Majorana flat bands in the Kitaev model on a Bishamon-kikko lattice", Jul. 5 (oral talk), 22nd International Conference on Magnetism (ICM2024) [Jun. 30 - Jul. 5, 2024 (Bologna, Italy)].

9. ○Sogen Ikegami, Kiyu Fukui, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, "Topological phase diagram of the Haldane model on a Bishamon-kikko--honeycomb lattice", P08 (poster), CEMS Topical Meeting on Emergent Phenomena in Topological Quantum Materials [May 20 - 21, 2024 (Saitama, Japan)].

10. Kiyu Fukui and Yukitoshi Motome, "Topological Majorana flat bands in the Kitaev model on a Bishamon-kikko lattice", P03 (poster), CEMS Topical Meeting on Emergent Phenomena in Topological Quantum Materials [May 20 - 21, 2024 (Saitama, Japan)].

11. Kiyu Fukui, Yasuyuki Kato, and Yukitoshi Motome, "Effect of a magnetic field on the Kitaev model coupled to environment", W22.00009 (oral talk), APS March Meeting 2024 [March 3 - 8, 2024 (Minneapolis, USA)].

12. Kiyu Fukui, "Functional renormalization group study in extensions of the Kitaev model", 72 (poster), 15th Symposium on Discovery, Fusion, Creation of New Knowledge by Multidisciplinary Computational Sciences [Oct. 2 - 3, 2023 (Tsukuba, Japan)].

13. Kiyu Fukui, Yasuyuki Kato, and Yukitoshi Motome, "Effect of a magnetic field on the Kitaev model coupled to environment", T5-3 (oral talk), (STATPHYS28 Satellite Meeting) Physics of Open Systems and Beyond (POS&BYD) [Aug. 17 - 23, 2023 (Sapporo, Japan)].

14. Kiyu Fukui, Yasuyuki Kato, and Yukitoshi Motome, "Effect of a magnetic field on the Kitaev model coupled to environment", PS1-22 (poster), International Conference on Quantum Liquid Crystals 2023 (QLC2023) [Aug. 8 - 10, 2023 (Sapporo, Japan)]

15. Kiyu Fukui, Yasuyuki Kato, and Yukitoshi Motome, "Magnetic-field Induced Transitions in the Kitaev Model Coupled to the Environment", 10-1369 (poster), International Conference on Strongly Correlated Electron Systems 2023 (SCES2023) [July 2 - 7, 2023 (Incheon, Korea)].

16. Kiyu Fukui, "Functional Renormalization group study on the effect of carrier doping into Kitaev materials", 2-30 (poster), The 30th Anniversary Symposium of the Center for Computational Science at the University of Tsukuba [Oct 13 - 14, 2022 (Tsukuba, Japan)]

17. Kiyu Fukui, Yasuyuki Kato, Joji Nasu, and Yukitoshi Motome, "Feasibility study of Kitaev quantum spin liquid for ultracold polar molecules and higher spin materials", P20-SF3A-30 (poster), 29th International Conference on LOW TEMPERATURE PHYSICS [August 18 - 24, 2022 (Sapporo, Japan)].

18. Kiyu Fukui, Yasuyuki Kato, Joji Nasu, and Yukitoshi Motome, "Feasibility study of Kitaev quantum spin liquid for ultracold polar molecules and higher spin materials", #245 (poster), International Conference on Strongly Correlated Electron Systems 2022 (SCES2022) [July 24 - 29, 2022 (Amsterdam, The Netherlands)].

19. Kiyu Fukui, Yasuyuki Kato, Joji Nasu, and Yukitoshi Motome, "Feasibility study of Kitaev quantum spin liquid: effects of long-range dipolar interactions and higher spin S > 1/2", T39 (poster), 11th International Conference on Highly Frustrated Magnetism 2022 (HFM2022) [June 20 - 25, 2022 (Paris, France)].

20. Kiyu Fukui, Yasuyuki Kato, Joji Nasu, and Yukitoshi Motome, "Ground state phase diagram of the Kitaev-Heisenberg model with general spin S", F51.00013 (oral talk), APS March Meeting 2022 [March 14 - 18, 2022 (Chicago, Online)].

21. Kiyu Fukui, Yasuyuki Kato, Joji Nasu, and Yukitoshi Motome, "Pseudo-fermion Functional Renormalization Group Study on the Feasibility of Kitaev Quantum Spin Liquid", PS1-20 (poster), International Conference on Quantum Liquid Crystal 2021 (QLC2021) [May 11 - 13, 2021 (Online)].

22. Kiyu Fukui and Yusuke Kato, "Even- and Odd-Frequency Superconductivity in Q1D Organic Superconductors under Magnetic Field", P26.28 (poster), International Symposium on Quantum Fluids and Solids 2018 (QFS2018) [July 25 ‒ 31, 2018 (Tokyo, Japan)].

Domestic

1. ○Sogen Ikegami, Kiyu Fukui, Rico Pohle, and Yukitoshi Motome, "Multipole Orders and Quantum Spin Liquids in S=3/2 Quantum Spin Models", 44 (poster), 計算物理春の学校 2025 [Mar. 10 - 14, 2025 (Okinawa)].

2. Kiyu Fukui, "汎関数繰り込み群によるキタエフスピン液体実現可能性の研究", oral talk, 第20回量子スピン系研究会 (20th workshop on quantum spin systems) [Dec. 13-14, 2024 (Akita)].

3. Kiyu Fukui and Yukitoshi Motome, "毘沙門亀甲格子上のキタエフ模型におけるトポロジカルマヨラナフラットバンド", PA-4 (poster), 物性研究所スパコン共同利用・CCMS合同研究会「計算物質科学の現在と未来」[Apr. 3 - 4, 2024 (ISSP)].

4. Kiyu Fukui and Yukitoshi Motome, "Topological Majorana flat bands in the Kitaev model on a Bishamon-kikko lattice", P05 (poster), FYR05 QLC meeting (令和5年度 QLC領域研究会), [Dec. 26 - 28, 2023 (ISSP)].

5. Kiyu Fukui, Yasuyuki Kato, and Yukitoshi Motome, "環境と結合したキタエフ模型における磁場誘起転移", PB-1 (poster), 物性研究所スパコン共同利用・CCMS合同研究会「計算の時代における物性科学」[Apr. 3 - 4, 2023 (ISSP)]. *優秀ポスター賞 (poster award) 

6. Kiyu Fukui, "汎関数繰り込み群を用いたキタエフスピン液体研究", C4 (oral talk), キタエフ量子スピン液体研究の新展開 ~マヨラナ粒子の創出と制御によるトポロジカル量子計算の実現に向けて~ [Aug. 3 - 5, 2021 (Online)]. *Invited

7. Kiyu Fukui, ”汎関数繰り込み群による量子スピン液体候補物質の物性解明", oral talk, FY2020 Results Presentation Session for Selected Projects (Supercomputing Division, Information Technology Center, The University of Tokyo) [June 10, 2021 (Online)]. *Invited

8. Kiyu Fukui and Yusuke Kato, "Odd- and Even-frequency Superconductivity in (TMTSF)_2X under magnetic field", 005 (poster), 第11回物性科学領域横断研究会「凝縮系科学の最前線」[Nov. 17 - 18, 2017 (ISSP)]. 

9. Kiyu Fukui, "Pairing Symmetry in Quasi-1-dimension lattice under Magnetic Field (磁場中の擬1次元格子系における超伝導対称性)", D-7 (oral talk), 61st Condensed Matter Physics Summer School [July 29 - August 2, 2016]. *Best presentation award

Japan Physical Society Meetings

1. ○Sogen Ikegami, Kiyu Fukui, Rico Pohle, and Yukitoshi Motome, "Higher-order spin interactions and multipole orders in S = 3/2 quantum spin systems (S=3/2量子スピン系における高次スピン相互作用と多極子秩序)", 16aSK312-12 (oral talk), 80th Annual Meeting [Sept. 16 - 19, 2025 (Hiroshima Univ.)].

2. Kiyu Fukui and Yukitoshi Motome, "Unveiling diverse magnetic phases in extended Kitaev models on a three-dimensional hyperhoneycomb lattice (3次元ハイパーハニカム格子上の拡張キタエフ模型における多彩な磁気相の解明)", 18pSK313-3 (oral talk), 80th Annual Meeting [Sept. 16 - 19, 2025 (Hiroshima Univ.)].

3. ○Masato Okamoto, Tatsuya Miki, Tatsuaki Mori, Kiyu Fukui, Shintaro Hoshino, and Hiroaki Ikeda, "Electron chirality and axial currents in magnetic materials (磁性体における電子カイラリティおよび軸性カレント)", 17aPS-90 (poster), 80th Annual Meeting [Sept. 16 - 19, 2025 (Hiroshima Univ.)].

4. ○Shosei Isobe, Tatsuaki Mori, Kiyu Fukui, and Hiroaki Ikeda, "Temperature dependence of specific heat across the BCS–BEC crossover in a two-band square lattice model (2バンド正方格子モデルにおけるBCS-BECクロスオーバーの比熱の温度依存性)", 18aPS-69 (poster), 80th Annual Meeting [Sept. 16 - 19, 2025 (Hiroshima Univ.)].

5. Kiyu Fukui and Yukitoshi Motome, "Ground-state phase diagram of the Kitaev-Γ model on a three-dimensional hyperhoneycomb lattice (3次元ハイパーハニカム格子キタエフ-Γ模型の基底状態相図)", 19aH1-5 (oral talk), 2025 Spring Meeting [Mar. 18 - 21, 2025 (Online)].

6. ○Sogen Ikegami, Kiyu Fukui, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, "Disorder and local topology on a Bishamon-kikko–honeycomb lattice (毘沙門亀甲-ハニカム格子における乱れと局所トポロジー)", 17aE318-9 (oral talk), 79th Annual Meeting [Sept. 16 - 19, 2024 (Hokkaido Univ.)].

7. ○Sogen Ikegami, Kiyu Fukui, Shun Okumura, Yasuyuki Kato, and Yukitoshi Motome, "Topological phase diagram for the Haldane model on a Bishamon-kikko--honeycomb lattice (毘沙門亀甲－ハニカム格子上のHaldane模型におけるトポロジカル相図)", 20aD1-3 (oral talk), 2024 Spring Meeting [Mar. 18 - 21, 2024 (Online)].

8. Kiyu Fukui and Yukitoshi Motome, "Topological Majorana flat bands in the Kitaev model on a Bishamon-kikko lattice (毘沙門亀甲格子上のキタエフ模型におけるトポロジカルマヨラナフラットバンド)", 20pH2-4 (oral talk), 2024 Spring Meeting [Mar. 18 - 21, 2024 (Online)].

9. Kiyu Fukui, Yasuyuki Kato, and Yukitoshi Motome, "Skin effect and edge states in the non-Hermitian Kitaev model in a magnetic field (磁場中の非エルミートキタエフ模型における表皮効果と端状態)", 19aA401-5 (oral talk), 78th Annual Meeting [Sept. 16 - 19, 2023 (Tohoku Univ.)].

10. Kiyu Fukui, Yasuyuki Kato, and Yukitoshi Motome, "Topological transitions induced by a magnetic field in the non-Hermitian Kitaev model (非エルミートキタエフ模型における磁場誘起トポロジカル転移)", 23aH3-9 (oral talk), 2023 Spring Meeting [Mar. 22 - 25, 2023 (Online)].

11. Kiyu Fukui, Yasuyuki Kato, and Yukitoshi Motome, "Ground-state phase diagram of the Kitaev-Heisenberg model on a three-dimensional hyperhoneycomb lattice (3次元ハイパーハニカム格子Kitaev-Heisenberg模型の基底状態相図)", 13pW541-1 (oral talk), 2022 Autumn Meeting [Sept. 12 - 15, 2022 (Tokyo Tech.)].

12. Kiyu Fukui, Yasuyuki Kato, Joji Nasu, and Yukitoshi Motome, "Ground state phase diagrams of spin S > 1/2 Kitaev-Heisenberg model (スピン S > 1/2 Kitaev-Heisenberg模型の基底状態相図)", 20pH1-3 (oral talk), 2021 Autumn Meeting [Sept. 20 - 23, 2021 (Online)].

13. Kiyu Fukui, Yasuyuki Kato, Joji Nasu, and Yukitoshi Motome, "On the realization of Kitaev quantum spin liquid in ultracold polar molecule systems: functional renormalization group study (冷却極性分子系でのKitaev量子スピン液体の実現について: 汎関数繰り込み群による研究)", 13aH2-1 (oral talk), 76th Annual Meeting [March 12 - 15, 2021 (Online)].

14. Kiyu Fukui and Yusuke Kato, "Pairing Symmetry of Bechgaard Salts with Frequency Dependence under Magnetic Field II (Bechgaard 塩の周波数依存性を含めた磁場中超伝導対称性 II)", 16pS301-9 (oral talk), 74th Annual Meeting [March 14 - 17, 2019 (Kyushu Univ.)].

15. Kiyu Fukui and Yusuke Kato, "Pairing Symmetry of Bechgaard Salts with Frequency Dependence under Magnetic Field (Bechgaard 塩の周波数依存性を含めた磁場中超伝導対称性)", 9pB203-4 (oral talk), 2018 Autumn Meeting [Sept. 9 - 12, 2018 (Doshisha Univ.)].

16. Kiyu Fukui and Yusuke Kato, "Even-frequency Mixing Effect on Odd-frequency Superconductivity in Quasi-one-dimensional Strongly Correlated Electron Systems under Magnetic Field (磁場下の強相関電子系における奇周波数超伝導に対する偶周波数成分の混合効果)", 25aK403-10 (oral talk), 73rd Annual Meeting [March 22 - 25, 2018 (Tokyo Univ. of Science)].

17. Kiyu Fukui and Yusuke Kato, "Magnetic Field Effect on Odd-frequency Superconductivity in Quasi-one-dimensional Strongly Correlated Electron Systems (擬1次元強相関電子系における奇周波数超伝導に対する磁場の効果)", 20aL22-11 (oral talk), 72nd Annual Meeting [March 17 - 20, 2017 (Osaka Univ.)].

Seminars (invited)

1. "Feasibility study of the Kitaev spin liquid and exploration of novel quantum phenomena of the Majorana fermions", Theory of Quantum Matter Unit (Nic Shannon Group), Okinawa Institute of Science and Technology (OIST) [Oct. 29, 2024].

2. [第100回] "模型の拡張によるキタエフスピン液体の実現可能性の探索: 汎関数繰り込み群による研究", Online CMT Seminars (オンライン物性理論セミナー), Online [May 28, 2024].

3. "Kitaev量子スピン液体の実現可能性の探索と磁場中における環境への散逸の効果の解明", Tetsuro Nikuni Group, Tokyo University of Science [July 14, 2023].

4. "Effect of magnetic field on the Kitaev model coupled to environment", Fundamental Physics Seminar (joint seminar of Ueda Gr., Tsuji Gr., Ashida Gr., and Gong Gr.), The University of Tokyo [June 26, 2023].

5. "Feasibility study of quantum spin liquid in extensions of the Kitaev model", ISSP TheorySeminar, The Institute for Solid State Physics, The University of Tokyo [June 16, 2023].

6. "Functional renormalization group study on extensions of the Kitaev model: higher spin materials, 3D lattices, and ultracold polar molecules", Joint Lab "Theory of Quantum Magnetism" (Freie Universität Berlin & Helmholtz-Zentrum Berlin for Materials and Energy, Head of the group: Prof. Dr. Johannes Reuther), Berlin [May 11, 2023].

7. "Kitaevスピン液体実現可能性の汎関数繰り込み群による研究 (Study on feasibility of Kitaev spin liquid by functional renormalization group)", Fujimoto-Mizushima Group, Osaka University [Dec. 5, 2022].

8. "磁場中の擬1次元強相関電子系における奇周波数・偶周波数超伝導の混合 (Mixing of odd-frequency and even-frequency pairings in Quasi-one-dimensional Strongly Correlated Electron Systems under Magnetic Field)", Yukio Tanaka Group, Nagoya University [August 28, 2017].