Search for massive Dirac state by NMR and transport measurements

• Project/Area Number: 24654101
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: Miyagawa Kazuya 東京大学, 工学(系)研究科(研究院), 助教 (90302760)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2014: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2013: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: ディラック電子系 / 有機導体 / 核磁気共鳴 / 輸送現象測定 / 輸送現象 / 電子相関 / 電荷秩序 / 圧力

Outline of Final Research Achievements

Due to linear dispersion in band structure, a mass of carrier in Dirac Fermion state is expected to be zero. However, theoretical studies predict carrier get mass in some special cases. We investigate the electronic state of organic bulk masless Dirac Fermion system, a,q-(BEDT-TTF)2I3 by transport and NMR measurements.
We found the different temperature dependence between lower pressure and higher pressure Dirac states in transport and NMR properties of a-(BEDT-TTF)2I3.
We obtained the new information of Dirac state where it is believed that there is no pressure dependence of character of carrier.

Research Products

• [Journal Article] Electronic States and Molecular Dynamics of Single-Component Molecular Conductor [M(tmdt)2] (M=Ni, Pt) Studied by 13C and 1H NMR (2016)
  • Author(s): R. Takagi, K. Miyagawa, M. Yoshimura, H. Gangi and K. Kanoda
  • Journal Title: Physical Review B Volume: 93 Issue: 2 Pages: 024403-024403
  • DOI: 10.1103/physrevb.93.024403
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Electrical Transport in the Quasi-Two-Dimensional Ionic Mott Insulator M2P-TCNQF4 under High Pressures (2015)
  • Author(s): R. Takehara, K. Miyagawa, T. Miyamoto, H. Okamoto, H. Taniguchi, K. Matsubayashi, Y. Uwatoko, and K. Kanoda
  • Journal Title: Journal of the Physical Society of Japan Volume: 84 Issue: 10 Pages: 104702-104702
  • DOI: 10.7566/jpsj.84.104702
  • NAID: 210000133700
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Quantum Spin Liquid Emerging from Antiferromagnetic Order by Introducing Disorder (2015)
  • Author(s): T. Furukawa, K. Miyagawa, T. Itou, M. Ito, H. Taniguchi, M. Saito, S. Iguchi, T. Sasaki and K. Kanoda
  • Journal Title: Physical Review Letters Volume: 115 Issue: 7 Pages: 077001-077001
  • DOI: 10.1103/physrevlett.115.077001
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Quantum criticality of Mott transition in organic materials (2015)
  • Author(s): Tetsuya Furukawa, Kazuya Miyagawa, Hiromi Taniguchi, Reizo Kato, Kazushi Kanoda
  • Journal Title: Nature Physics Volume: 11 Issue: 3 Pages: 221-224
  • DOI: 10.1038/nphys3235
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Pressure-Induced Mott Transition in an Organic Superconductor with a Finite Doping Level (2015)
  • Author(s): H. Oike, K. Miyagawa, H. Taniguchi, K. Kanoda
  • Journal Title: Phys. Rev. Lett. Volume: １１４ Issue: 6 Pages: 670021-5
  • DOI: 10.1103/physrevlett.114.067002
  • Peer Reviewed / Open Access
• [Journal Article] Electron transport in TTF-CA under high pressures (2014)
  • Author(s): R. Takehara, K. Miyagawa, K. Kanoda, T. Miyamoto, H. Matsuzaki, H. Okamoto, H. Taniguchi, K. Matsubayashi, Y. Uwatoko
  • Journal Title: Physica B: Condensed Matter Volume: 460 Pages: 83-87
  • DOI: 10.1016/j.physb.2014.11.045
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Evidence of Andreev bound states as a hallmark of the FFLO phase in κ-(BEDT-TTF)2Cu(NCS)2 (2014)
  • Author(s): H. Mayaffre, S. Kramer, M. Horvatic, C. Berthier, K. Miyagawa, K. Kanoda, V. F. Mitrovic
  • Journal Title: Nature Physics Volume: 10 Issue: 12 Pages: 928-932
  • DOI: 10.1038/nphys3121
  • Peer Reviewed
• [Journal Article] Pressure-temperature phase diagram of a charge-ordered organic conductor studied by 13C NMR (2014)
  • Author(s): T. Itou, K. Miyagawa, J. Nakamura, K. Kanoda, K. Hiraki, and T. Takahashi
  • Journal Title: Physical Review B Volume: 90 Issue: 4
  • DOI: 10.1103/physrevb.90.045126
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Emergence of non-equilibrium charge dynamics in a charge-cluster glass (2014)
  • Author(s): T. Sato, F. Kagawa, K. Kobayashi, K. Miyagawa, K. Kanoda, R. Kumai, Y. Murakami, Y. Tokura
  • Journal Title: Physical Review B Volume: 89 Issue: 12 Pages: 121102-121106
  • DOI: 10.1103/physrevb.89.121102
  • Peer Reviewed
• [Journal Article] Charge-cluster glass in an organic conductor (2013)
  • Author(s): F. Kagawa, T. Sato, K. Miyagawa, K. Kanoda, Y. Tokura, K. Kobayashi, R. Kumai
  • Journal Title: Nature Physics Volume: (掲載決定) Issue: 7 Pages: 419-422
  • DOI: 10.1038/nphys2642
  • Peer Reviewed
• [Presentation] 有機ディラック電子系における量子ホールスピン強磁性状態のNMR研究 (2016)
  • Author(s): 平田倫啓, 谷口智隆, Hadrien Mayaffre, 宮川和也, 田村雅史, Steffen Krmer, Mladen Horvati, Claude Berthier, 鹿野田一司
  • Organizer: 日本物理学会第71回年次大会
  • Place of Presentation: 東北学院大 (宮城県仙台市)
  • Year and Date: 2016-03-19
• [Presentation] Pressure dependence of the in-plane magnetoresistance in the Dirac fermion phase of α-(BEDT-TTF)2I3 (2016)
  • Author(s): Dong Liu, Kazuya Miyagawa, Masafumi Tamura, Kazushi Kanoda
  • Organizer: 日本物理学会第71回年次大会
  • Place of Presentation: 東北学院大 (宮城県仙台市)
  • Year and Date: 2016-03-19
• [Presentation] 有機Dirac電子系a-(BEDT-TTF)2I3の高磁場下13C-NMR (2016)
  • Author(s): 松野学, 宮川和也, 田村雅史, 鹿野田一司
  • Organizer: 日本物理学会第71回年次大会
  • Place of Presentation: 東北学院大 (宮城県仙台市)
  • Year and Date: 2016-03-19
• [Presentation] 有機Dirac電子系α-(BEDT-TTF)2I3の高磁場下13C-NMRの磁場角度依存性 (2015)
  • Author(s): 松野学, 宮川和也, 田村雅史, 鹿野田一司
  • Organizer: 日本物理学会2015年秋季大会
  • Place of Presentation: 関西大 (大阪府吹田市)
  • Year and Date: 2015-09-16
• [Presentation] 傾斜Diracコーン系 α-(ET)2I3の電子間相互作用効果のNMR研究 (2015)
  • Author(s): 平田倫啓, 石川恭平, 宮川和也, 田村雅史, Claude Berthier, Denis Basko, 松野元樹, 小林晃人, 鹿野田一司
  • Organizer: 日本物理学会2015年秋季大会
  • Place of Presentation: 関西大 (大阪府吹田市)
  • Year and Date: 2015-09-16
• [Presentation] 13C NMR study of α-(BEDT-TTF)2I3 under pressure (2015)
  • Author(s): Dong Liu, Kazuya Miyagawa, Masafumi Tamura, Kazushi Kanoda
  • Organizer: 日本物理学会2015年秋季大会
  • Place of Presentation: 関西大 (大阪府吹田市)
  • Year and Date: 2015-09-16
• [Presentation] NMR Studies on the Superconducting State of an Organic Doped Mott Insulator with a Isotropic Triangular Lattice, k-(BEDT-TTF)4Hg2.89Br8 (2015)
  • Author(s): Kazuya Miyagawa
  • Organizer: The 11th International Conference on Materials and Mechanisms of Superconductivity (M2S2015)
  • Place of Presentation: Geneva (Swiss)
  • Year and Date: 2015-08-23
  • Int'l Joint Research
• [Presentation] Magnetic field dependence of 6 K anomaly in spin liquid state of k-(BEDT-TTF)2Cu2(CN)3 investigated by 13C NMR (2015)
  • Author(s): Kazuya Miyagawa
  • Organizer: 20th International Conference on Magnetism (ICM2015)
  • Place of Presentation: Barcelona (Spain)
  • Year and Date: 2015-07-05
  • Int'l Joint Research
• [Presentation] 13C NMR study of a-(BEDT-TTF)2I3 under pressure (2015)
  • Author(s): Dong Liu，Kazuya Miyagawa，Masafumi Tamura，Kazushi Kanoda
  • Organizer: 日本物理学会 第70回年次大会
  • Place of Presentation: 早稲田大学、東京都
  • Year and Date: 2015-03-21 – 2015-03-24
• [Presentation] Anomalous Charge Fluctuations in The Organic Conductor, b-(DMBEDT-TTF)2PF6 (2014)
  • Author(s): K. Miyagawa, A. Inoue, K. Kanoda, T. Isono, A. Ueda, H. Mori
  • Organizer: The 27th International Conference on Low Temperature Physics (LT27)
  • Place of Presentation: ブエノスアイレス、アルゼンチン
  • Year and Date: 2014-08-06 – 2014-08-13
• [Presentation] Site-Selective NMR Study on an Organic-Inorganic Hybrid Compound (DI-DCNQI) 2Cu with pi-d Mixing Controlled by Pressure (2014)
  • Author(s): K. Miyagawa, S. Nakayama, K. Hiraki, T. Takahashi, K. Kanoda
  • Organizer: International Conference on Strongly Correlated Electron Systems (SCES2014)
  • Place of Presentation: グルノーブル、フランス
  • Year and Date: 2014-07-07 – 2014-07-11
• [Presentation] NMR studies of phase transition form a metallic state to a Dirac-electron state in the organic system, θ-(BEDT-TTF)2I3 (2014)
  • Author(s): K, Miyagawa
  • Organizer: APS March Meeting 2014
  • Place of Presentation: デンバー(アメリカ)
• [Presentation] 13C NMR study on the interplay between charge-ordered and Dirac Fermion phases in α-(BEDT-TTF)2I3 under the critical pressure range (2014)
  • Author(s): Dong Liu，Kazuya Miyagawa，Masafumi Tamura，Kazushi Kanoda
  • Organizer: 日本物理学会 第69回年次大会
  • Place of Presentation: 東海大学 (神奈川県)
• [Presentation] 有機ディラック電子系おけるNMR測定 (2013)
  • Author(s): 宮川和也
  • Organizer: 固体中におけるディラック電子系物理の新展開
  • Place of Presentation: 京都大学 (京都)
• [Presentation] 13C NMR studies on the organic Massless Dirac Fermion materials (2013)
  • Author(s): Kazuya Miyagawa
  • Organizer: The 10th International Symposium on Crystalline Organic Metals Superconductors and Ferromagnets (ISCOM2013)
  • Place of Presentation: モントリオール(カナダ)
• [Presentation] Transport investigation of α-(BEDT-TTF)2I3 under intermediated presures (2013)
  • Author(s): Dong Liu，Kazuya Miyagawa，Kazushi Kanoda，Masafumi Tamura
  • Organizer: 日本物理学会 2013年秋季大会
  • Place of Presentation: 徳島大学 (徳島県)
• [Presentation] θ-(BEDT-TTF)2I3における電子相関効果 (2012)
  • Author(s): 平田倫啓，宮川和也，田村雅史，鹿野田一司
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学(神奈川)