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Theoretical study of the heavy electron state in Lanthanide and Actinide compounds

Research Project

Project/Area Number 62540258
Research Category

Grant-in-Aid for General Scientific Research (C)

Allocation TypeSingle-year Grants
Research Field 物性一般(含極低温・固体物性に対する理論)
Research InstitutionTOHOKU UNIVERSITY

Principal Investigator

TACHIKI Masashi  Institute for Materials Research, Tohoku University, 金属材料研究所, 教授 (20028111)

Co-Investigator(Kenkyū-buntansha) TAKAHASHI Saburo  Institute for Materials Research, Tohoku University, 金属材料研究所, 助手 (60171485)
KOYAMA Tomio  Institute for Materials Research, Tohoku University, 金属材料研究所, 助手 (30153696)
MAEKAWA Sadamichi  Department of Engineering, Nagoya University, 工学部, 教授 (60005973)
Project Period (FY) 1987 – 1988
Project Status Completed (Fiscal Year 1988)
Budget Amount *help
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1988: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
KeywordsHeavy electron system / Anderson lattice / Density of states / Spin fluctuations / スピンのゆらぎ / 酸化物高温超伝導体 / 周期的アンダーソンモデル / セリウム化合物 / ウラニウム化合物
Research Abstract

The f electron system in most of Lanthanide and Actinide compounds is considered as a localized electron system. However, in some of the compounds such as CeCu_2Si_2 and UBe_<13> in these groups behaves as a Fermiliquid with an extremely large effective mass at low temperatures. This Fermi liquid state is called the heavy electron state. To understand the origin and nature of this state is one of the most fundamental problems in solid state physics.
Our major purpose of the present project is to understand the low energy electronic state of the heavy electron system. For this purpose we calculated the density of states in the low energy region using the periodic Anderson model. The obtained result shows that a very sharp peak in the density of states curve appears near the Fermi level at low temperatures when the large renormalization effect due to the f electron spin fluctuations exists in the self-energy correction for the f and s electrons in the system. This narrow band corresponds to the well-defined one-fermion excitation with a very large effective mass. As temperature increases, our calculation shows that the narrow peak broadens and its height decreases due to a shortening of the quasi-particle lifetime. This result is consistent with the experimental result observed in the heavy electon systems which shows the crossover from the heavy electon state to the Kondo-impurity-like state.
We also investigated the mechanism of superconductivity in the hight superconducting oxides because we believe that the superconducting oxides are classified into the heavy-electron superconductors. We proposed a possible mechanism for high temperature superconductivity based on the charge-fluctuation-mechanism. The anomalous temperature dependence of the nuclear relaxation time-of cu nucleus in YBCO was successfully explained.

Report

(3 results)
  • 1988 Annual Research Report   Final Research Report Summary
  • 1987 Final Research Report Summary
  • Research Products

    (39 results)

All Other

All Publications (39 results)

  • [Publications] T.Koyama.: Phys.Rev.B. 36. 437-451 (1987)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] T.Koyama.: Jpn.J.Appl.Phys.26. Suppl.26. 473-474 (1987)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] T.Koyama.: Jpn.J.Appl.Phys.26. Suppl.26. 475-476 (1987)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M.Tachiki.: Jpn.J.Appl.Phys.26. Suppl.26. 493-494 (1987)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M.Tachiki.: Kagaku. 58. 359-368 (1987)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M.Tachiki.: Physica C. 153-155. 239-240 (1988)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] T.Koyama.: Physica C. 153-155. 1317-1318 (1988)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M.Tachiki.: Phys.Rev.B. 38. 218-224 (1988)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M.Tachiki.: Phys.Rev.B. 39. 293-299 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] T.Koyama.: Phys.Rev.B. 39. 2279-2292 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M.Tachiki.: to be published in Solid State Communication.

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] T. Koyama: "Theory of the Anderson lattice at finite temperatures" Phys. Rev. B. 36. 437-451 (1987)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] T. Koyama: "Theory for the Heavy-Fermion State in Anderson Lattice" Jpn. J. Appl. Phys.Suppl. 26. 473-474 (1987)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] T. Koyama: "The Loop-Expansion Method in Anderson Model" Jph. J. Appl. Phys.Suppl. 26. 475-476 (1987)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M. Tachiki: "Dynamical Spin-Susceptibility in Heavy Fermion Systems" Jpn. J. Appl. Phys.Suppl. 26. 493-494 (1987)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M. Tachiki: "Mechanism of high temperature superconductivity in the oxides" Kagaku. 58. 359-368 (1987)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M. Tachiki: "Strong Enhancement of Electron-Phonon Interaction due to Charge Fluctuations in Oxide Superconductors and Their High T_C Superconductivity" Physica C. 153-155. 239-240 (1988)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] T. Koyama: "Charge Fluctuations and superconductivity in Superconducting Oxides" Physica C. 153-155. 1317-1318 (1988)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M. Tachiki: "Pairing interaction mediated by the Cu-O charge-transfer oscillations associated with LO phonons in oxide superconductors and their high-T_C superconductivity" Phys. Rev. B. 38. 218-224 (1988)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M. Tachiki: "Charge-fluctuation mechanism of high-T_c superconductivity and the isotope effect in oxide superconductors" Phys. Rev. B. 39. 293-299 (1989)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] T. Koyama: "Theory of unclear relaxation in superconducting high-T_C oxides" Phys. Rev. B. 39. 2279-2292 (1989)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] M. Tachiki: "Strong Vortex Pinning Intrinsic in High-T_C Oxide Superconductors" to be published in Solid State Communication.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1988 Final Research Report Summary
  • [Publications] T.Koyama: Phys.Rev.B. 36. 437-451 (1987)

    • Related Report
      1988 Annual Research Report
  • [Publications] T.Koyama: Jpn.J.Appl.Phys.26. Suppl.26. 473-474 (1987)

    • Related Report
      1988 Annual Research Report
  • [Publications] T.Koyama: Jpn.J.Appl.Phys.26. Suppl.26. 475-476 (1987)

    • Related Report
      1988 Annual Research Report
  • [Publications] M.Tachiki: Jpn.J.Appl.Phys.26. Suppl.26. 493-494 (1987)

    • Related Report
      1988 Annual Research Report
  • [Publications] M.Tachiki: Kagaku. 58. 359-368 (1987)

    • Related Report
      1988 Annual Research Report
  • [Publications] M.Tachiki: Physica C. 153-155. 239-240 (1988)

    • Related Report
      1988 Annual Research Report
  • [Publications] T.Koyama: Physica C. 153-155. 1317-1318 (1988)

    • Related Report
      1988 Annual Research Report
  • [Publications] M.Tachiki: Phys.Rev.B. 38. 218-224 (1988)

    • Related Report
      1988 Annual Research Report
  • [Publications] M.Tachiki: Phys.Rev.B. 39. 293-299 (1989)

    • Related Report
      1988 Annual Research Report
  • [Publications] T.Koyama: Phys.Rev.B. 39. 2279-2292 (1989)

    • Related Report
      1988 Annual Research Report
  • [Publications] M.Tachiki: to be published in Solid State Communication.

    • Related Report
      1988 Annual Research Report
  • [Publications] S.Takahashi and M.Tachiki: Phys.Rev.B. 35. 145-150 (1987)

    • Related Report
      1987 Final Research Report Summary
  • [Publications] T.Koyama and M. Tachiki: Phys. Rev.B. 36. 437-451 (1987)

    • Related Report
      1987 Final Research Report Summary
  • [Publications] T.Koyama and M.Tachiki: JJAP(Proc.18th Int.Conf. onLow Temoerature Physics,Kyoto). 26,Suppl.26-3. 473-474 (1987)

    • Related Report
      1987 Final Research Report Summary
  • [Publications] T.Koyama and M.Tachiki: JJAP (proc.18th Int.Cong on Low Temperature Physics,Kyoto). 26,SUPPL.26-3. 475-476 (1987)

    • Related Report
      1987 Final Research Report Summary
  • [Publications] M.Tachiki,S.Takahashi and T.Koyama: JJAP (proc.18th Int.Cong on Low Temperature Physics,Kyoto). 26,SUPPL.26-3. 493-494 (1987)

    • Related Report
      1987 Final Research Report Summary
  • [Publications] M.Tachiki and S.Takahashi: To be publishes in physica.

    • Related Report
      1987 Final Research Report Summary

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Published: 1987-04-01   Modified: 2016-04-21  

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