Magnon excitations vs. spinon excitations in spontaneously symmetry broken antiferromagnets in two dimensions

• Project/Area Number: 18H01183
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Yunoki Seiji 国立研究開発法人理化学研究所, 開拓研究本部, 主任研究員 (70532141)
• Co-Investigator(Kenkyū-buntansha): 白川 知功 国立研究開発法人理化学研究所, 計算科学研究センター, 上級研究員 (40571237) ; 曽田 繁利 国立研究開発法人理化学研究所, 計算科学研究センター, 技師 (60466414) ; 正木 晶子 国立研究開発法人理化学研究所, 計算科学研究センター, 研究員 (00620717)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥17,160,000 (Direct Cost: ¥13,200,000、Indirect Cost: ¥3,960,000); Fiscal Year 2020: ¥6,630,000 (Direct Cost: ¥5,100,000、Indirect Cost: ¥1,530,000); Fiscal Year 2019: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000); Fiscal Year 2018: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
• Keywords: 磁気励起 / 数値計算 / 三角格子ハイゼンベルグ模型 / 励起ダイナミックス / スピン励起 / 量子磁性体 / スピンS=1/2反強磁性ハイゼンベルグ模型 / 量子スピンダイナミックス / 分数励起 / 大規模数値計算

Outline of Final Research Achievements

We have performed various numerical simulations to evaluate magnetic excitation spectrum for SU(2) symmetric spin S=1/2 antiferromagnetic Heisenberg models on the square and triangular lattices, where the ground states are spontaneously symmetry broken to show Neel orders. We have found some indications for the absence of well defined coherent magnon excitations and the existence of incoherent excitations continuing unto very high energy, which are not simply explained by the spin wave theory. Furthermore, we have compared our numerical results with several experiments and found a good quantitative agreement.

Academic Significance and Societal Importance of the Research Achievements

最近接相互作用のみを持つ正方格子スピンS=1/2反強磁性ハイゼンベルグ模型など基底状態が自発的対称性が破れたSU(2)対称なスピンS=1/2反強磁性ハイゼンベルグ模型の磁気励起はスピン波理論を基とするS=1マグノン励起で記述できると考えられている。これは低エネルギー領域では正しいが高エネルギー領域では必ずしも正しいわけではない。最新の数値計算を駆使することにより、このことを示す計算結果が提供できた。

Research Products

• [Journal Article] Effect of phase string on single-hole dynamics in the two-leg Hubbard ladder (2021)
  • Author(s): Shinjo Kazuya、Sota Shigetoshi、Tohyama Takami
  • Journal Title: Physical Review B Volume: 103 Issue: 3 Pages: 035141-035141
  • DOI: 10.1103/physrevb.103.035141
  • Peer Reviewed
• [Journal Article] Phase transitions in the frustrated Ising ladder with stoquastic and nonstoquastic catalysts (2021)
  • Author(s): K. Takada, S. Sota, S. Yunoki, B. Pokharel, H. Nishimori, D. A. Lidar
  • Journal Title: Physical Review Research Volume: 3 Issue: 4 Pages: 043013-043013
  • DOI: 10.1103/physrevresearch.3.043013
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Resonating dimer-monomer liquid state in a magnetization plateau of a spin-1/2 kagome-strip Heisenberg chain (2021)
  • Author(s): K. Morita, S. Sota, T. Tohyama
  • Journal Title: Communications Physics Volume: 4 Issue: 1 Pages: 161-161
  • DOI: 10.1038/s42005-021-00665-6
  • Peer Reviewed / Open Access
• [Journal Article] Magnetic phase diagrams of the spin-1/2 Heisenberg model on a kagome-strip chain: Emergence of a Haldane phase (2021)
  • Author(s): K. Morita, S. Sota, T. Tohyama
  • Journal Title: Physical Review B Volume: 104 Issue: 22 Pages: 224417-224417
  • DOI: 10.1103/physrevb.104.224417
  • Peer Reviewed
• [Journal Article] Symmetry-adapted variational quantum eigensolver (2020)
  • Author(s): Seki Kazuhiro、Shirakawa Tomonori、Yunoki Seiji
  • Journal Title: Physical Review A Volume: 101 Issue: 5 Pages: 052340-052340
  • DOI: 10.1103/physreva.101.052340
  • Peer Reviewed
• [Journal Article] Thermodynamic properties of an S=12 ring-exchange model on the triangular lattice (2020)
  • Author(s): Seki Kazuhiro、Yunoki Seiji
  • Journal Title: Physical Review B Volume: 101 Issue: 23 Pages: 235115-235115
  • DOI: 10.1103/physrevb.101.235115
  • Peer Reviewed
• [Journal Article] Magnetic excitations in magnetization plateaus of a frustrated spin ladder (2020)
  • Author(s): Sasaki Kota、Sugimoto Takanori、Tohyama Takami、Sota Shigetoshi
  • Journal Title: Physical Review B Volume: 101 Issue: 14 Pages: 144407-144407
  • DOI: 10.1103/physrevb.101.144407
  • NAID: 130007646102
  • Peer Reviewed
• [Journal Article] Gapless spin liquid in a square-kagome lattice antiferromagnet (2020)
  • Author(s): M. Fujihala, K. Morita, R. Mole, S. Mitsuda, T. Tohyama, S. Yano, D. Yu, S. Sota, T. Kuwai, A. Koda, H. Okabe, H. Lee, S. Itoh, T. Hawai, T. Masuda, H. Sagayama, A. Matsuo, K. Kindo, S. Ohira-Kawamura, and K. Nakajima
  • Journal Title: Nature Communications Volume: 11 Issue: 1 Pages: 3429-3429
  • DOI: 10.1038/s41467-020-17235-z
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Proximate Kitaev system for an intermediate magnetic phase in in-plane magnetic fields (2020)
  • Author(s): Kim Beom Hyun、Sota Shigetoshi、Shirakawa Tomonori、Yunoki Seiji、Son Young-Woo
  • Journal Title: Physical Review B Volume: 102 Issue: 14 Pages: 140402-140402
  • DOI: 10.1103/physrevb.102.140402
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Spin Dynamics in the t?t′?J Model: Dynamical Density-Matrix Renormalization Group Study (2020)
  • Author(s): Tohyama Takami、Sota Shigetoshi、Yunoki Seiji
  • Journal Title: Journal of the Physical Society of Japan Volume: 89 Issue: 12 Pages: 124709-124709
  • DOI: 10.7566/jpsj.89.124709
  • NAID: 40022438374
  • Peer Reviewed
• [Journal Article] Quantum annealing for systems of polynomial equations (2019)
  • Author(s): C. C. Chang, A. Gambhir, T. S. Humble, S Sota
  • Journal Title: Scientific Reports Volume: 9 Issue: 1 Pages: 10258-10258
  • DOI: 10.1038/s41598-019-46729-0
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Machine Learning Phase Diagram in the Half-filled One-dimensional Extended Hubbard Model (2019)
  • Author(s): Shinjo Kazuya、Sasaki Kakeru、Hase Satoru、Sota Shigetoshi、Ejima Satoshi、Yunoki Seiji、Tohyama Takami
  • Journal Title: Journal of the Physical Society of Japan Volume: 88 Issue: 6 Pages: 065001-065001
  • DOI: 10.7566/jpsj.88.065001
  • NAID: 210000156011
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Quantum Monte Carlo study of the superfluid density in quasi-one-dimensional systems of hard-core bosons: Effect of the suppression of phase slippage (2019)
  • Author(s): A. Masaki-Kato, S. Yunoki, D. S. Hirashima
  • Journal Title: Physical Review B Volume: 100 Issue: 22 Pages: 224515-224515
  • DOI: 10.1103/physrevb.100.224515
  • Peer Reviewed
• [Journal Article] Two-dimensional ground-state mapping of a Mott-Hubbard system in a flexible field-effect device (2019)
  • Author(s): Y. Kawasugi, K. Seki, S. Tajima, J. Pu, T. Takenobu, S. Yunoki, H. M. Yamamoto, and R. Kato
  • Journal Title: Science Advances （掲載決定） Volume: なし Issue: 5
  • DOI: 10.1126/sciadv.aav7282
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Mechanism of superconductivity and electron-hole doping asymmetry in κ-type molecular conductors (2019)
  • Author(s): Watanabe Hiroshi、Seo Hitoshi、Yunoki Seiji
  • Journal Title: Nature Communications Volume: 10 Issue: 1 Pages: 3176-3176
  • DOI: 10.1038/s41467-019-11022-1
  • Peer Reviewed
• [Journal Article] Non-Fermi-liquid behavior and doping asymmetry in an organic Mott insulator interface (2019)
  • Author(s): Kawasugi Yoshitaka、Seki Kazuhiro、Pu Jiang、Takenobu Taishi、Yunoki Seiji、Yamamoto Hiroshi M.、Kato Reizo
  • Journal Title: Physical Review B Volume: 100 Issue: 11 Pages: 115141-115141
  • DOI: 10.1103/physrevb.100.115141
  • Peer Reviewed
• [Journal Article] Dynamical density matrix renormalization group study of spin and charge excitations in the four-leg t-t′-J ladder (2018)
  • Author(s): Tohyama Takami、Mori Michiyasu、Sota Shigetoshi
  • Journal Title: Physical Review B Volume: 97 Issue: 23 Pages: 235137-235137
  • DOI: 10.1103/physrevb.97.235137
  • Peer Reviewed
• [Journal Article] Ground state phase diagram of the Kitaev-Heisenberg model on a honeycomb-triangular lattice (2018)
  • Author(s): Kishimoto Masanori、Morita Katsuhiro、Matsubayashi Yukihiro、Sota Shigetoshi、Yunoki Seiji、Tohyama Takami
  • Journal Title: Physical Review B Volume: 98 Issue: 5
  • DOI: 10.1103/physrevb.98.054411
  • Peer Reviewed
• [Journal Article] Spin transport through a spin-1/2 XXZ chain contacted to fermionic leads (2018)
  • Author(s): F. Lange, S. Ejima, T. Shirakawa, S. Yunoki, and H. Fehske
  • Journal Title: Physical Review B Volume: 97 Issue: 24
  • DOI: 10.1103/physrevb.97.245124
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Variational cluster approach to thermodynamic properties of interacting fermions at finite temperatures: A case study of the two-dimensional single-band Hubbard model at half filling (2018)
  • Author(s): K. Seki, T. Shirakawa, and S. Yunoki
  • Journal Title: Physical Review B Volume: 98 Issue: 20
  • DOI: 10.1103/physrevb.98.205114
  • Peer Reviewed
• [Presentation] kagome strip鎖における磁化プラトーを示す量子スピン液体状態 (2021)
  • Author(s): 森田克洋、曽田繁利、遠山貴巳
  • Organizer: 日本物理学会2021年秋季大会
• [Presentation] 動的密度行列繰り込み群法による三角格子反強磁性ハイゼンベルク模型の励起ダイナミクスの解析 (2021)
  • Author(s): 曽田繁利、遠山貴巳、白川知功、柚木清司
  • Organizer: 第8回「京」を中核とするHPCIシステム利用研究課題 成果報告会
• [Presentation] 動的密度行列繰り込み群法による三角格子反強磁性ハイゼンベルク模型の励起ダイナミクスの解析 (2020)
  • Author(s): 曽田繁利、遠山貴巳、白川知功、柚木清司
  • Organizer: 第7回「京」を中核とするHPCIシステム利用研究課題 成果報告会
• [Presentation] 銅酸化物高温超伝導体の磁気励起：動的密度行列繰り込み群法によるt -t’-J模型の動的スピン構造因子の計算 (2020)
  • Author(s): 遠山貴巳、曽田繁利、柚木清司
  • Organizer: 第7回「京」を中核とするHPCIシステム利用研究課題 成果報告会
• [Presentation] 三角格子ハイゼンベルグ模型の動的スピン構造因子 (2019)
  • Author(s): 白川知功、曽田繁利、柚木清司、遠山貴巳
  • Organizer: 日本物理学会2019年秋季大会
• [Presentation] Dynamical DMRG Study of Spin Excitation Dynamics on the Triangular Lattice Antiferromagnetic Heisenberg model (2019)
  • Author(s): S. Sota, T. Shirakawa, S. Yunoki, T. Tohyama
  • Organizer: International Conference on Strongly Correlated Electron Systems 2019
  • Int'l Joint Research
• [Presentation] 密度行列繰り込み群法による強相関量子ダイナミクスシミュレータの開発と応用 (2019)
  • Author(s): 曽田繁利
  • Organizer: 第6回「京」を中核とするHPCIシステム利用研究課題成果報告会
• [Presentation] 動的密度行列繰り込み群法による三角格子反強磁性ハイゼンベルク模型の励起ダイナミクスの解析 (2019)
  • Author(s): 曽田繁利、白川知功、柚木清司、遠山貴巳
  • Organizer: 第6回「京」を中核とするHPCIシステム利用研究課題成果報告会
• [Presentation] 大規模並列密度行列繰り込み群法の開発と量子ダイナミクスへの応用 (2019)
  • Author(s): 曽田繁利
  • Organizer: 物性研究所スパコン共同利用・CCMS合同研究会「計算物質科学の新展開」
  • Invited
• [Presentation] Massively parallel density matrix renormalization group method algorithm for two-dimensional strongly correlated systems and its applications (2019)
  • Author(s): S. Sota, T. Tohyama, and S. Yunoki
  • Organizer: The 1st International R-CCS Symposium
• [Presentation] 三角格子反強磁性Heisenberg模型における量子スピン液体状態とスピン励起ダイナミクス (2019)
  • Author(s): 曽田繁利, 柚木清司, 遠山貴己
  • Organizer: 日本物理学会第74回年次大会
• [Presentation] スピン1/2三角格子Heisenberg反強磁性体の磁気励起：数値計算による解析 (2018)
  • Author(s): 柚木清司
  • Organizer: 日本物理学会2018年秋季大会(シンポジウム講演)
  • Invited
• [Presentation] Spin dynamics in two-dimensional S=1/2 antiferromagnet ― fate of single magnon excitations ― (2018)
  • Author(s): S. Yunoki
  • Organizer: Workshop Quantum Many body States 2018
  • Int'l Joint Research / Invited
• [Presentation] 三角格子量子スピン系Ba3CoSb2O9の非弾性中性子散乱の解析 (2018)
  • Author(s): 曽田繁利, 白川知功, 柚木清司, 遠山貴己
  • Organizer: H30年度ポスト「京」重点課題（７）第3回CDMSI研究会
• [Presentation] Dynamical DMRG study of excitation dynamics of triangular lattice antiferromagnetic Heisenberg models (2018)
  • Author(s): S. Sota, T. Shirakawa, T. Tohyama, and S. Yunoki
  • Organizer: TNSAA 2018-2019