Study of spin liquid states under geometrical frustration

• Project/Area Number: 20840026
• Research Category: Grant-in-Aid for Young Scientists (Start-up)
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics II
• Research Institution: Kyoto University
• Principal Investigator: YAMASHITA Minoru Kyoto University, 理学研究科, 助教 (10464207)
• Project Period (FY): 2008 – 2009
• Project Status: Completed (Fiscal Year 2009)
• Budget Amount: ¥3,276,000 (Direct Cost: ¥2,520,000、Indirect Cost: ¥756,000); Fiscal Year 2009: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2008: ¥1,716,000 (Direct Cost: ¥1,320,000、Indirect Cost: ¥396,000)
• Keywords: 磁性 / 低温物性 / 物性実験

Research Abstract

To explore the nature of spin excitations of spin liquid material, we have measured thermal conductivity of organic compounds κ-(BEDT-TTF)_2Cu_2(CN)_3 and EtMe_3Sb[Pd(dmit)_2]_2, which are known to possess no-long-range ordered stat-so called "spin liquid state"-down to the lowest temperature. We found the excitation of κ-(BEDT-TTF)_2Cu_2(CN)_3 is gapped, so it is a gapped spin liquid. On the other hand, thermal conductivity of EtMe_3Sb[Pd(dmit)_2]_2 shows a temperature dependence very similar to metal, even though the material is insulator.

Research Products

• [Journal Article] Highly Mobile Gapless Excitations in a Two-Dimensional Candidate Quantum Spin Liquid (2010)
  • Author(s): Minoru Yamashita.
  • Journal Title: Science (掲載予定)
  • Peer Reviewed
• [Journal Article] Thermal conductivity measurements of the energy-gap anisotropy of superconducting LaFePO at low temperatures (2009)
  • Author(s): Minoru Yamashita.
  • Journal Title: Physical Review B Vol.80 Pages: 220509-220511
  • Peer Reviewed
• [Journal Article] Thermal-transport measurements in a quantum spin-liquid state of the frustrated triangular magnetκ-(BEDT-TTF)2Cu2(CN)3 (2009)
  • Author(s): Minoru Yamashita.
  • Journal Title: Nature Physics Vol.5 Pages: 44-47
  • Peer Reviewed
• [Journal Article] Thermal conductivity measurements of the energy-gap anisotropy of superconducting LaFePO at low temperatures (2009)
  • Author(s): M.Yamashita
  • Journal Title: Physical Review B 80 Pages: 220509-220511
  • Peer Reviewed
• [Journal Article] Therma-transport measurements in a quantum spin-liquid state of the frustrated triangular magnet κ-(BEDT-TTF)2Cu2(CN)3 (2009)
  • Author(s): Minoru Yamashita
  • Journal Title: Nature Physics 5 Pages: 44-47
  • Peer Reviewed
• [Presentation] Thermal-transport measurement in a gapless spin-liquid state of EtMeSb[Pd(dmit)] (2010)
  • Author(s): 山下穣
  • Organizer: 322APS March Meeting 2010
  • Place of Presentation: Portland, Oregon, USA
  • Year and Date: 2010-03-17
• [Presentation] Thermal-transport measurement in a gapless spin-liquid state of EtMe3Sb[Pd(dmit)2]2 (2010)
  • Author(s): 山下穣
  • Organizer: APS March Meeting 2010
  • Place of Presentation: Portland, Oregon, USA
  • Year and Date: 2010-03-17
• [Presentation] 熱伝導率測定による鉄系超伝導体LaFePOの超伝導対称性の決定 (2009)
  • Author(s): 山下穣
  • Organizer: 日本物理学会 2009年秋季大会
  • Place of Presentation: 熊本大学
  • Year and Date: 2009-09-25
• [Presentation] 有機モット絶縁体kappa-(BEDT-TTF)2Cu2(CN)3のスピン液体状態における熱輸送測定II (2009)
  • Author(s): 中田宣人
  • Organizer: 日本物理学会2008年秋季大会
  • Place of Presentation: 岩手大学、岩手
  • Year and Date: 2009-09-23
• [Presentation] Thermal-transport Measurements in Spin-1/2 Triangular Antiferromagnetsκ-(BEDT-TTF)2Cu2(CN)3 EtMe3Sb[Pd(dmit)2]2 (2009)
  • Author(s): 山下穣
  • Organizer: The 8th International Symposium on Crystalline Organic Metal Superconductors and Ferromagnets
  • Place of Presentation: ヒルトソニセコビレッジ北海道
  • Year and Date: 2009-09-14
• [Presentation] Thermal-transport Measurements in Spin-1/2 Triangular Antiferromagnets κ-(BEDT-TTF)2Cu2(CN)3 and (2009)
  • Author(s): 山下穣
  • Organizer: The 8th International Symposium on Crystalline Organic Metals, Superconductors and Ferromagnets
  • Place of Presentation: ヒルトンニセコビレッジ
  • Year and Date: 2009-09-14
• [Presentation] Thermal-transport measurements of spin-liquid statesκ-(BEDT-TTF)2Cu2(CN)3 (2009)
  • Author(s): 山下穣
  • Organizer: 25th International Confrernce on Low Temperature Physic
  • Place of Presentation: Amsterdam, Netherlands
  • Year and Date: 2009-08-09
• [Presentation] Thermal-transport measurements of spin-liquid states of k-(BEDT-TTF)2Cu2(CN)3 (2009)
  • Author(s): 山下穣
  • Organizer: 25th International Conference on Low Temperature Physics
  • Place of Presentation: Amsterdam, Netherlands
  • Year and Date: 2009-08-09
• [Presentation] 二次元三角格子反強磁性体EtMe3Sb[Pd(dmit)2]2のにおける熱輸送測定 (2009)
  • Author(s): 山下穣
  • Organizer: 日本物理学会第64回年次大会
  • Place of Presentation: 立教道大学、池袋
  • Year and Date: 2009-03-27
• [Presentation] 二次元三角格子反強磁性体EtMe3Sb[Pd(dmit)2]2のスピン液体状態における熱輸送測定 (2009)
  • Author(s): 山下穣
  • Organizer: 日本物理学会第64回年次大会
  • Place of Presentation: 立教大学、池袋
  • Year and Date: 2009-03-27
• [Presentation] Gapped quantum spin-liquid state in a frustrated triangularκ-(BEDT-TTF)2Cu2(CN)3 (2009)
  • Author(s): 山下穣
  • Organizer: APS March Meegin
  • Place of Presentation: Pittsburgh, PA, USA
  • Year and Date: 2009-03-16
• [Presentation] Gapped quantum spin-liquid state in a frustrated triangular magnet kappa-(BEDT-TTF)2Cu2 (2009)
  • Author(s): 山下穣
  • Organizer: APS March Meeging 2009
  • Place of Presentation: Pittsburgh, PA, USA
  • Year and Date: 2009-03-16