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Theoretical Study of Kondo lattices by the 1/d expansion method

Research Project

Project/Area Number 13640342
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 固体物性Ⅱ(磁性・金属・低温)
Research InstitutionHokkaido University

Principal Investigator

OHKAWA Fusayoshi  Hokkaido Uiuveisity, Graduate School of Sci., Piofessor, 大学院・理学研究科, 教授 (00107442)

Project Period (FY) 2001 – 2003
Project Status Completed (Fiscal Year 2003)
Budget Amount *help
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2001: ¥1,700,000 (Direct Cost: ¥1,700,000)
Keywordstheory of Kondo lattices / 1 / d expansion / high-temperature superconductivity / itinerant-election magnetism / pseudogaps / Mott-Hubbard metal-insulator transition / election-phonon interaction / multiple Q SDW / アンダードープ領域 / 強相関電子系 / 遍歴電子反強磁性 / 超交換相互作用 / 近藤格子 / 遍歴電子強磁性 / flat-band模型 / band-edge模型 / multiple SDW構造
Research Abstract

I have developed a theoiy of Kondo lattices for past 16 yeais ; an eaily theoiy of high-temperature superconductivity published in 1987 is also within this theoretical framework. I have applied the theory to the following five issues on strong election correlations : (1)Itinerant-electron ferromagnetism : The supeiexchange interaction can be ferromagnetic for multi-band models, when the Hund coupling is strong enough. The exchange interaction arising from the virtual exchange of pair excitations of quasiparticles can also be ferromagnetic, when the chemical potential is at one of the band edges, in particular, when a sharp peak of the density of states is there. These two exchange interactions are mainly responsible for ferromagnetism in itinerant-election systems. (2)Magnetic structures of itinerant-electron antiferromagnets : When there are equivalent nesting vectors, multiple Q spin density wave (SDW) states can be stabilized ; magnetizations with different Q should be orthogonal to each other for double or triple Q SDW. (3)Pseudogaps in normal states of high-temperature superconductors : Anisotropic pseudogaps can appear because of large life-time widths of quasiparticles, which are mainly caused by dγ-wave superconducting fluctuations. (4)Election-phonon interaction in high-temperature superconductors : I have proposed a novel electron-phonon interaction arising from the modulation of the superexchange interaction by phonons. This election-phonon interaction can explain kinks in the quasiparticle dispersion and the softening of phonons m cuprates. (5)Mott-Hubbard metal-insulator crossover in disordered Kondo lattices : The asymmetry of the crossovei between hole-doped and electron-doped cuprates can be explained by a theory of disordered Kondo lattices, if disorder of hole-doped cuprates is relatively larger than that of election-doped cuprates.

Report

(4 results)
  • 2003 Annual Research Report   Final Research Report Summary
  • 2002 Annual Research Report
  • 2001 Annual Research Report
  • Research Products

    (10 results)

All Other

All Publications (10 results)

  • [Publications] Fusayoshi J.Ohkawa: "Theory of itinerant-electron ferromagnetism"Physical Review B. 65. 174424(1)-174424(16) (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Fusayoshi J.Ohkawa: "Magnetic and charge structures in itinerant-electron magnets : Coexistence of multiple spin-density and charge-density waves"Physical Review B. 66. 014408(1)-014408(10) (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Fusayoshi J.Ohkawa: "Application of Kondo-lattice theory to high-temperature superconductivity and pseudogaps in cuprate oxides"Physical Review B. 69. 104502(1)-104502(16) (2004)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] OHKAWA, Fusayoshi J: "Theory of itinerant-election ferromagnetism"Physical Review B. 65. 174424(1-16) (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] OHKAWA, Fusayoshi J: "Magnetic and charge structures in itinerant-election magnets : Coexistence of multiple spin-density and charge-density waves"Physical Review B. 66. 014408(1-10) (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] OHKAWA, Fusayoshi J: "Application of Kondo-lattice theory to high-temperature superconductivity and pseudogaps in cuprate oxides"Physical Review B. 69. 104502(1-16) (2004)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] Fusayoshi J.Ohkawa: "Application of Kondo-lattice theory to high-temperature superconductivity and pseudogaps in cuprate oxides"Physical Review B. 69(印刷中). (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] Fusayoshi J.Ohkawa: "Theory of itinerant-electron ferromagnetism"Physical Review B. 65. 174424-1-174424-16 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Fusayoshi J.Ohkawa: "Magnetic and charge structures in itinerant-electron magnets : Coexistence of multiple spin-density and charge-density waves"Physical Review B. 66. 014408-1-014408-10 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Hiroyuki Satoh, Fusayoshi J.Ohkawa: "Theory of the metamagnetic crossover in CeRu_2Si_2"Physical Review B. 63. 184401-1-13 (2001)

    • Related Report
      2001 Annual Research Report

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Published: 2001-04-01   Modified: 2020-05-15  

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