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Study of relaxation phenomena in strongly fluctuating quantum syetems

Research Project

Project/Area Number 06640503
Research Category

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

Allocation TypeSingle-year Grants
Research Field 物性一般(含基礎論)
Research InstitutionOsaka University (1995)
Kyoto University (1994)

Principal Investigator

MIYASHITA Seiji  Faculty of Science Professor, 理学部, 教授 (10143372)

Co-Investigator(Kenkyū-buntansha) 川崎 辰夫  京都大学, 総合人間学部, 教授 (40025367)
冨田 博之  京都大学, 総合人間学部, 教授 (70025477)
Project Period (FY) 1994 – 1995
Project Status Completed (Fiscal Year 1995)
Budget Amount *help
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
Keywordsquantum fluctuation / metastable state / phase transition / 量子ゆらぎ / 準安定性 / トンネル効果 / モンテカルロ法 / 核形成
Research Abstract

We study relaxation phenomena from metastable states which appear in the ordered states below the critical points. In particular, we study the cases at very low temperatures where no thermal fluctuation are expected and the syatem is in freezing state in classical sense. Even in such cases, system still can relax through quantum fluctuations. In order to clarify mechanisms of such relazation by quantum fluctuation, we developed method to investigate dynamical property of quantum system. For example, purely quantum mechanical method (Schrodinger equation), reduced density matrix method, etc.
The study includes quantum tunneling phenomena, Landau-Zener process. For quantum tunneling phenomena we proposed direct approach to the phenomana and it could give a complementary understanding of the phenomana to the field theoretical methods which are popular recently.

Report

(3 results)
  • 1995 Annual Research Report   Final Research Report Summary
  • 1994 Annual Research Report
  • Research Products

    (24 results)

All Other

All Publications (24 results)

  • [Publications] P. A. Rikvold, H. Tomita, S. Miyashita and S. W. Sides: "Metastable lifetimes in a kinetic Ising model: Dependence on field and systetm size" Phys. Rev.52. 9174-9177 (1995)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] S. Yamamoto and S. Miyashita: "Magnetization of S=1 antiferromagnetic Heisenberg chains" Phys. Rev.B51. 3649-3654 (1995)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] S. Miyashita, S. Yamamoto and T. Nakamura: "Quantum Monte Carlo Studies on Low Dimensional Spin Systems" Computational Physics as a New Frotier in condensed Matter Research, ed. H. Takayama, et al (J. Phys. Soc. Jpn. 1995) pp.171-179. 171-179 (1995)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] S. Miyashita: "Dynamics of the Magnetization with an Inversion of the Magnetic Field" J. Phys. Soc. Jpn.64. 3207-3214 (1995)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] A. Kuroda and S. Miyashita: "Existence of Phase Transition in Ising-like Heisenberg Antiferromagnets on the Kagome Lattice" J. Phys. Soc. Jpn.64. 4509-4512 (1995)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] M. Roji and S Miyashita: "Competition between Classical Ordered State and Quantum State in Ferromagnetic Chains Coupled by Antiferromagetic Bonds." J. Phys. Soc. Jpn.65(印刷中). (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] P.A.Rikvold, H.Tomita, S.Miyashita and S.W.Sides: "Metastable lifetimes in a kinetic Ising model : Dependence on field and systetm size" Phys.Rev.E 49. 5080-5090 (1994)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] S.Yamamoto and S.Miyashita: "Magnetization of S=1 antiferromagnetic Heisenberg chains" Phys.Rev.B51. 3649-3654 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] S.Miyashita, S.Yamamoto and T.Nakamura: "Quantum Monte Carlo Studies on Low Dimensional Spin Systems" Computational Physics as a New Frotier in Condensed Matter Research, ed. H.Takayama, et al (J.Phys.Soc.Jpn.1995). 171-179

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] S.Miyashita: "Dynamics of the Magnetization with an Inversion of the Magnetic Field" J.Phys.Soc.Jpn. 64. 3207-3214 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] A.Kuroda and S.Miyashita: "Existence of Phase Transition in Ising-like Heisenberg Antiferromagnets on the Kagome Lattice" J.Phys.Soc.Jpn.64. 4506-4512 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] M.Roji and S.Miyashita: "Competition between Classical Ordered State and Quantum State in Ferromagnetic Chains Coupled by Antiferromagetic Bonds" J.Phys.Soc.Jpn.65. 883-886 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] P.A.Rikvold,H.Tomita,S.Miyashita and S.W.Sides: "Metastable Iifetimes in a Kinetic Ising model : Dependence on field and systetm size" Phys.Rev.52. 9174-9177 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] S.Yamamoto and S.Miyashita: "Magnetization of S=1 antiferromagnetic Heisenberg chains" Phys.Rev.B51. 3649-3654 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] S.Miyashita,S.Yamamoto and T.Nakamura: "Quantum Monte Carlo Studies on Low Dimensional Spin Systems" Computational Physics as a New Frotier in Condensed Matter Research,ed.H.Takayama,et al (J.Phys.Soc.Jpn.1995) pp.171-179. 171-179 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] S.Miyashita: "Dynamics of the Magnetization with an Inversion of the Magnetic Field" J.Phys.Soc.Jpn.64. 3207-3214 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] A.Kuroda and S.Miyashita: "Existence of Phase Transition in Ising-like Heisenberg Antiferromagnets on the Kagome Lattice" J.Phys.Soc.Jpn.64. 4509-4512 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] M.Roji and S.Miyashita: "Competition between Classical Ordered State and Quantum State in Ferromagnetic Chains Coupled by Antiferromagetic Bonds" J.Phys.Soc.Jpn.65(印刷中). (1996)

    • Related Report
      1995 Annual Research Report
  • [Publications] 宮下精二: "Transfer-Matrix Monte Carlo Method-A Practical Solution for the Negati Sign Proble" J.Phys.Soc.Japan. 63. 2449-2452 (1994)

    • Related Report
      1994 Annual Research Report
  • [Publications] 山本昌司: "World-Line Monte Carlo Study of the Dispersion Relation of an S=1" J.Phys.Soc.Japan. 63. 2866-2869 (1994)

    • Related Report
      1994 Annual Research Report
  • [Publications] 渡会征三: "Thermodynamic Properties of Ising-Like Heisenberg Autifenomignet" J.Phys.Soc.Japan. 63. 1916-1927 (1994)

    • Related Report
      1994 Annual Research Report
  • [Publications] 山本昌司: "Anisotropy effects on the magnetic properties of an S=1" Physical Review. B50. 6277-6288 (1994)

    • Related Report
      1994 Annual Research Report
  • [Publications] Per Arne Rikvold: "Metastable lifetime in a kivetic Ising model" Physical Review. E49. 5080-5090 (1994)

    • Related Report
      1994 Annual Research Report
  • [Publications] 川崎辰夫: "Metastable Behavior in Relaxation Process of XY Fuzzy Spin Model" Progress of Theoretical Physics. 93. 47-54 (1995)

    • Related Report
      1994 Annual Research Report

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Published: 1994-04-01   Modified: 2016-04-21  

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