非平衡動的平均場理論の展開と低次元強相関系への応用

• Project Area: Materials Design through Computics: Complex Correlation and Non-equilibrium Dynamics
• Project/Area Number: 25104709
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: The University of Tokyo
• Principal Investigator: 辻 直人 東京大学, 理学(系)研究科(研究院), 助教 (90647752)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2013: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 非平衡 / 強相関 / 動的平均場理論

Outline of Annual Research Achievements

本年度は、(1)非平衡強相関系を扱うための手法開発、特に非平衡動的平均場理論の拡張、および(2)それらの手法を超伝導体に適用して新たな物理現象の解析に応用すること、の主に二つのテーマに取り組んだ。
(1) 非平衡動的平均場理論は強相関系の非平衡現象を扱う強力な解析手法として確立されているが、その限界は自己エネルギーを局所近似することにある。我々は前年度に引き続き、非平衡動的平均場理論をクラスター拡張した非平衡動的クラスター理論の開発を行った。これにより、クラスター内の短距離の非局所的な相関効果を取り込みながら系の時間発展を計算することができるようになった。しかし、現実的な計算量の範囲ではクラスターは2x2などの小さいサイズに制限される。さらに長距離の非局所相関効果を考慮するために、動的平均場理論(DMFT)と揺らぎ交換近似(FLEX)を組み合わせた新しい手法(FLEX+DMFT)を提案した。これはDMFTにより自己エネルギーの局所部分を、FLEXによりそれ以外の非局所部分を長距離まで自己無撞着に取り入れる方法論である。FLEX+DMFTを2次元のハバード模型に適用し、ドーム状のd波超伝導相図を得た。ドーム構造はFLEX単独では見られなかった結果で、相関効果の特徴的なfilling依存性を反映している。
(2) 非平衡動的平均場理論を引力ハバード模型に適用して、振動電場によって定常的に駆動されている超伝導体のダイナミクスを調べた。その結果、超伝導秩序パラメーターが振動電場の2倍の周波数で強制振動すること、振動電場の周波数が超伝導ギャップの半分になるところで秩序パラメーターの振動が発散的に増幅されることを見出した。これは超伝導体の集団励起モードであるヒッグスモードと外場による振動が共鳴したためと解釈される。相関効果によりヒッグスモードの寿命に反比例する共鳴幅が生じる。

Research Progress Status

26年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

26年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Interaction quench in the Holstein model: Thermalization crossover from electron- to phonon-dominated relaxation (2015)
  • Author(s): Yuta Murakami, Philipp Werner, Naoto Tsuji, and Hideo Aoki
  • Journal Title: Physical Review B Volume: 91 Issue: 4 Pages: 045128-045128
  • DOI: 10.1103/physrevb.91.045128
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Light-induced collective pseudospin precession resonating with Higgs mode in a superconductor (2014)
  • Author(s): Ryusuke Matsunaga, Naoto Tsuji, Hiroyuki Fujita, Arata Sugioka, Kazumasa Makise, Yoshinori Uzawa, Hirotaka Terai, Zhen Wang, Hideo Aoki, and Ryo Shimano
  • Journal Title: Science Volume: 345 Issue: 6201 Pages: 1145-1149
  • DOI: 10.1126/science.1254697
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Supersolid Phase Accompanied by a Quantum Critical Point in the Intermediate Coupling Regime of the Holstein Model (2014)
  • Author(s): Yuta Murakami, Philipp Werner, Naoto Tsuji, and Hideo Aoki
  • Journal Title: Physical Review Letters Volume: 113 Issue: 26 Pages: 266404-266404
  • DOI: 10.1103/physrevlett.113.266404
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Nonequilibrium dynamical cluster theory (2014)
  • Author(s): Naoto Tsuji, Peter Barmettler, Hideo Aoki, Philipp Werner
  • Journal Title: Physical Review B Volume: 90 Issue: 7
  • DOI: 10.1103/physrevb.90.075117
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Nonequilibrium dynamical mean-field theory and its applications (2014)
  • Author(s): Hideo Aoki, Naoto Tsuji, Martin Eckstein, Marcus Kollar, Takashi Oka, Philipp Werner
  • Journal Title: Reviews of Modern Physics Volume: 86 Issue: 2 Pages: 779-837
  • DOI: 10.1103/revmodphys.86.779
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Dynamical mean-field analysis of ordered phases in the half-filled Holstein-Hubbard model (2014)
  • Author(s): Yuta Murakami, Philipp Werner, Naoto Tsuji, and Hideo Aoki
  • Journal Title: JPS Conference Series Volume: 3
  • DOI: 10.7566/jpscp.3.016023
  • Peer Reviewed
• [Journal Article] Dynamical mean-field analysis of ordered phases in the half-filled Holstein-Hubbard model (2014)
  • Author(s): Yuta Murakami, Philipp Werner, Naoto Tsuji, Hideo Aoki
  • Journal Title: Journal of Physical Society Conference Proceedings Volume: 印刷中
  • Peer Reviewed
• [Journal Article] Ordered phases in the Holstein-Hubbard model: Interplay of strong Coulomb interaction and electron-phonon coupling (2013)
  • Author(s): Yuta Murakami, Philipp Werner, Naoto Tsuji, Hideo Aoki
  • Journal Title: Physical Review B Volume: 88 Issue: 12
  • DOI: 10.1103/physrevb.88.125126
  • Peer Reviewed
• [Journal Article] Nonequilibrium dynamical mean-field theory based on weak-coupling perturbation expansions: Application to dynamical symmetry breaking in the Hubbard model (2013)
  • Author(s): Naoto Tsuji, Philipp Werner
  • Journal Title: Physical Review B Volume: 88 Issue: 16 Pages: 165115-165115
  • DOI: 10.1103/physrevb.88.165115
  • Peer Reviewed
• [Journal Article] Nonthermal antiferromagnetic order and nonequilibrium criticality in the Hubbard model (2013)
  • Author(s): Naoto Tsuji, Martin Eckstein, Philipp Werner
  • Journal Title: Physical Review Letters Volume: 110 Issue: 13 Pages: 136404-136404
  • DOI: 10.1103/physrevlett.110.136404
  • Peer Reviewed
• [Presentation] Light-induced Higgs-mode resonance in s-wave and d-wave superconductors (2015)
  • Author(s): Naoto Tsuji
  • Organizer: Dynamics of Strongly Correlated Systems, ISSP-MPIPKS Joint Workshop
  • Place of Presentation: 東京大学物性研究所、千葉県
  • Year and Date: 2015-03-31
• [Presentation] 電子・格子系における非平衡超伝導の動的平均場理論による解析 (2015)
  • Author(s): 村上雄太、Philipp Werner、辻直人、青木秀夫
  • Organizer: 日本物理学会
  • Place of Presentation: 早稲田大学、東京都新宿区
  • Year and Date: 2015-03-23
• [Presentation] 強相関電子系の非平衡相転移の理論的研究 (2015)
  • Author(s): 辻直人
  • Organizer: 日本物理学会領域5若手奨励賞受賞講演
  • Place of Presentation: 早稲田大学、東京都新宿区
  • Year and Date: 2015-03-22
  • Invited
• [Presentation] d波超伝導体におけるヒッグスモード: 平均場理論からのアプローチ (2015)
  • Author(s): 辻直人、青木秀夫
  • Organizer: 日本物理学会
  • Place of Presentation: 早稲田大学、東京都新宿区
  • Year and Date: 2015-03-21
• [Presentation] 超伝導体における「ヒッグス粒子」 (2015)
  • Author(s): 辻直人
  • Organizer: 第3回統計物理学懇談会
  • Place of Presentation: 慶應大学、神奈川県
  • Year and Date: 2015-03-10
  • Invited
• [Presentation] Higgs mode in conventional and unconventional superconductors (2015)
  • Author(s): Naoto Tsuji
  • Organizer: A workshop on "Nonequilibrium phase transitions in diverse physical systems"
  • Place of Presentation: 東京大学、東京都文京区
  • Year and Date: 2015-03-09
  • Invited
• [Presentation] DMFT+FLEX approach to unconventional superconductivity (2015)
  • Author(s): Motoharu Kitatani, Naoto Tsuji, and Hideo Aoki
  • Organizer: APS 2015 March Meeting
  • Place of Presentation: San Antonio, Texas, USA
  • Year and Date: 2015-03-03
• [Presentation] DMFT + FLEX approach to anisotropic pairing superconductivity (2015)
  • Author(s): Motoharu Kitatani, Naoto Tsuji, and Hideo Aoki
  • Organizer: International Workshop on New Frontier of Numerical Methods for Many-Body Correlations
  • Place of Presentation: 東京大学、東京都文京区
  • Year and Date: 2015-02-20
• [Presentation] Light-induced Anderson pseudospin resonance with Higgs mode in superconductors (2014)
  • Author(s): Naoto Tsuji
  • Organizer: Nonequilibrium phenomena in novel quantum states (YKIS 2014)
  • Place of Presentation: 京都大学基礎物理学研究所、京都府
  • Year and Date: 2014-12-05
• [Presentation] Nonequilibrium dynamical cluster approximation: non-local correlation and real-time dynamics (2014)
  • Author(s): Naoto Tsuji
  • Organizer: International Symposium on Computics: Quantum simulation and design (ISC-QSD 2014)
  • Place of Presentation: 東京大学、東京都文京区
  • Year and Date: 2014-12-02
• [Presentation] Non-equilibrium DMFT study of thermalization in an electron-phonon system (2014)
  • Author(s): Yuta Murakami, Philipp Werner, Naoto Tsuji, and Hideo Aoki
  • Organizer: International Symposium on Computics: Quantum simulation and design (ISC-QSD 2014)
  • Place of Presentation: 東京大学、東京都文京区
  • Year and Date: 2014-12-02
• [Presentation] DMFT+FLEX approach to unconventional superconductivity (2014)
  • Author(s): Motoharu Kitatani, Naoto Tsuji, and Hideo Aoki
  • Organizer: International Symposium on Computics: Quantum simulation and design (ISC-QSD 2014)
  • Place of Presentation: 東京大学、東京都文京区
  • Year and Date: 2014-12-02
• [Presentation] 超伝導体における「ヒッグス粒子」の理論 (2014)
  • Author(s): 辻直人
  • Organizer: CMRC研究会「超伝導研究の新展開(鉄系・銅酸化物系+非平衡系)」
  • Place of Presentation: KEK、茨城県
  • Year and Date: 2014-11-18
  • Invited
• [Presentation] QMCソルバーを用いたDMFT+FLEX法による超伝導相図 (2014)
  • Author(s): 北谷基治、辻直人、青木秀夫
  • Organizer: 日本物理学会
  • Place of Presentation: 中部大学、愛知県
  • Year and Date: 2014-09-10
• [Presentation] 超伝導体におけるヒッグスモード共鳴の理論 (2014)
  • Author(s): 辻直人、青木秀夫
  • Organizer: 日本物理学会
  • Place of Presentation: 中部大学、愛知県
  • Year and Date: 2014-09-09
• [Presentation] 非平衡動的平均場によるホルスタイン・モデルの解析：フォノンの非平衡緩和現象への役割 (2014)
  • Author(s): 村上雄太、Philipp Werner、辻直人、青木秀夫
  • Organizer: 日本物理学会
  • Place of Presentation: 中部大学、愛知県
  • Year and Date: 2014-09-08
• [Presentation] Supersolid state and quantum critical point in the intermediate coupling regime of an electron-phonon system (2014)
  • Author(s): Yuta Murakami, Philipp Werner, Naoto Tsuji, and Hideo Aoki
  • Organizer: International Conference on Strongly Correlated Electron Systems (SCES 2014)
  • Place of Presentation: Grenoble, France
  • Year and Date: 2014-07-11
• [Presentation] Higgs Mode and Terahertz Nonlinear Optics in Superconductors (2014)
  • Author(s): Ryo Shimano, Ryusuke Matsunaga, Yuki Hamada, Arata Sugioka, Hiroyuki Fujita, Kazumasa Makise, Yoshinori Uzawa, Hirotaka Terai, Zhen Wang, Naoto Tsuji, and Hideo Aoki
  • Organizer: 19th International Conference on Ultrafast Phenomena (UP2014)
  • Place of Presentation: 沖縄県
  • Year and Date: 2014-07-10
  • Invited
• [Presentation] Anderson pseudospin resonance with Higgs mode in superconductors (2014)
  • Author(s): Naoto Tsuji
  • Organizer: New Horizon of Strongly Correlated Physics (NHSCP2014)
  • Place of Presentation: 東京大学物性研究所、千葉県
  • Year and Date: 2014-07-03
  • Invited
• [Presentation] Higgs mode and Anderson pseudospin resonance in superconductors (2014)
  • Author(s): Naoto Tsuji
  • Organizer: Higgs modes in condensed matter and quantum gases
  • Place of Presentation: 京都大学基礎物理学研究所、京都府
  • Year and Date: 2014-06-24
  • Invited
• [Presentation] Nonthermal fixed point in the antiferromagnetic Hubbard model
  • Author(s): Naoto Tsuji
  • Organizer: Non-equilibrium dynamics of correlated electron-systems
  • Place of Presentation: Krvavec, Slovenia
  • Invited
• [Presentation] Prethermalization and nonthermal fixed point in the Hubbard model
  • Author(s): Naoto Tsuji
  • Organizer: Interdisciplinary mini-workshop on nonequilibrium physics
  • Place of Presentation: 京都大学基礎物理学研究所、京都府
  • Invited
• [Presentation] 強相関電子系・超伝導体の非平衡理論
  • Author(s): 辻直人
  • Organizer: 日本物理学会シンポジウム「限界駆動の物質光科学」
  • Place of Presentation: 東海大学、神奈川県
  • Invited
• [Presentation] 非平衡動的クラスター理論
  • Author(s): 辻直人、Peter Barmettler、青木秀夫、Philipp Werner
  • Organizer: 日本物理学会
  • Place of Presentation: 東海大学、神奈川県
• [Presentation] 円偏光照射下のハニカム格子Hubbard模型の光誘起トポロジカル転移の理論
  • Author(s): 見上敬洋、辻直人、青木秀夫
  • Organizer: 日本物理学会
  • Place of Presentation: 東海大学、神奈川県
• [Presentation] s波超伝導体におけるHiggs modeの非平衡動的平均場理論
  • Author(s): 辻直人、青木秀夫
  • Organizer: 日本物理学会
  • Place of Presentation: 徳島大学、徳島県
• [Presentation] ホルスタイン・ハバード・モデルにおけるs波超伝導と電荷秩序の競合と共存
  • Author(s): 村上雄太、辻直人、Philipp Werner、青木秀夫
  • Organizer: 日本物理学会
  • Place of Presentation: 徳島大学、徳島県
• [Presentation] フェルミオン超流動における相互作用クエンチ
  • Author(s): 辻直人、Martin Eckstein、Philipp Werner
  • Organizer: 日本物理学会
  • Place of Presentation: 徳島大学、徳島県
• [Presentation] 非平衡動的クラスター理論の開発
  • Author(s): 辻直人
  • Organizer: 新学術「コンピューティクスによる物質デザイン: 複合相関と非平衡ダイナミクス」平成25年度第一回研究会
  • Place of Presentation: 東京大学、東京都文京区
• [Presentation] Holstein-Hubbardモデルにおける秩序相の競合と共存
  • Author(s): 村上雄太、Philipp Werner、辻直人、青木秀夫
  • Organizer: 第7回物性科学領域横断研究会
  • Place of Presentation: 東京大学、東京都文京区
• [Presentation] 非平衡動的クラスター理論とHubbard模型における相互作用クエンチへの適用
  • Author(s): 辻直人、Peter Barmettler、青木秀夫、Philipp Werner
  • Organizer: 第7回物性科学領域横断研究会
  • Place of Presentation: 東京大学、東京都文京区
• [Presentation] Nonequilibrium dynamical mean-field study of the nonthermal fixed point in the Hubbard model
  • Author(s): Naoto Tsuji, Martin Eckstein, Philipp Werner
  • Organizer: American Physical Society March Meeting
  • Place of Presentation: Denver, USA
• [Presentation] DMFT analysis of the superconductivity in the Holstein-Hubbard model -- Interplay of strong Coulomb interaction and electron-phonon coupling
  • Author(s): Yuta Murakami, Philipp Werner, Naoto Tsuji, Hideo Aoki
  • Organizer: American Physical Society March Meeting
  • Place of Presentation: Denver, USA
• [Presentation] Photo-induced topological phase transitions in the Hubbard model on honeycomb lattice
  • Author(s): Takahiro Mikami, Naoto Tsuji, Hideo Aoki
  • Organizer: American Physical Society March Meeting
  • Place of Presentation: Denver, USA
• [Presentation] Quantum interaction quench in the presence of a long-range order
  • Author(s): Naoto Tsuji
  • Organizer: Quantum Many Body Systems out of Equilibrium (QSOE13)
  • Place of Presentation: Dresden, Germany
• [Presentation] Dynamical phaes transition and nonequilibrium criticality in correlated fermion systems
  • Author(s): Naoto Tsuji, Martin Eckstein, Philipp Werner
  • Organizer: The International Conference on Strongly Correlated Electron Systems (SCES2013)
  • Place of Presentation: 東京大学、東京都文京区
• [Presentation] Quantum interaction quench in the presence of a long-range order
  • Author(s): Naoto Tsuji, Martin Eckstein, Philipp Werner
  • Organizer: Emergent Quantum Phases in Condensed Matter (EQPCM2013)
  • Place of Presentation: 東京大学物性研究所、千葉県
• [Presentation] Nonequilibrium dynamical cluster theory
  • Author(s): Naoto Tsuji, Peter Barmettler, Hideo Aoki, Philipp Werner
  • Organizer: Conference on: Ultrafast Dynamics of Correlated Materials
  • Place of Presentation: Trieste, Italy
• [Presentation] Ordered phases in the Holstein-Hubbard model: Interplay of strong electron-electron and electron-phonon interactions
  • Author(s): Yuta Murakami, Philipp Werner, Naoto Tsuji, Hideo Aoki
  • Organizer: The International Conference on Strongly Correlated Electron Systems (SCES2013)
  • Place of Presentation: 東京大学、東京都文京区
• [Presentation] Non-local correlations in real time: nonequilibrium dynamical cluster approximation
  • Author(s): Naoto Tsuji, Peter Barmettler, Philipp Werner, Hideo Aoki
  • Organizer: International workshop on Strong correlations and angle-resolved photoemission spectroscopy (CORPES13)
  • Place of Presentation: Hamburg, Germany
• [Presentation] Nonequilibrium superconducting phase transition in correlated electron systems
  • Author(s): Naoto Tsuji, Martin Eckstein, Philipp Werner
  • Organizer: Gordon Research Conference: Superconductivity
  • Place of Presentation: Les Diableret, Switzerland
• [Presentation] DMFT analysis for superconductivity in the Holstein-Hubbard model
  • Author(s): Yuta Murakami, Naoto Tsuji, Philipp Werner, Hideo Aoki
  • Organizer: Gordon Research Conference: Superconductivity
  • Place of Presentation: Les Diableret, Switzerland
• [Presentation] Dynamically induced antiferromagnetic phase transition in correlated electron systems
  • Author(s): Naoto Tsuji, Martin Eckstein, Philipp Werner
  • Organizer: International Workshop on Optical Terahertz Science and Technology (OTST 2013)
  • Place of Presentation: 京都テルサ、京都府
• [Book] 固体物理第48巻第9号 (2013)
  • Author(s): 辻直人、岡隆史、青木秀夫
  • Total Pages: 14
  • Publisher: アグネ技術センター