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Does a critical line exist in a spin-glass phase?

Research Project

Project/Area Number 24540413
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Research Field Mathematical physics/Fundamental condensed matter physics
Research InstitutionShibaura Institute of Technology

Principal Investigator

NAKAMURA Tota  芝浦工業大学, 工学部, 教授 (50280871)

Project Period (FY) 2012-04-01 – 2015-03-31
Project Status Completed (Fiscal Year 2014)
Budget Amount *help
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2013: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Keywordsスピングラス / モンテカルロシミュレーション / ベイズ推定 / 相関長 / スケーリング / 非平衡緩和解析 / 相転移 / 普遍性 / スピンカイラリティ / GPU計算
Outline of Final Research Achievements

Spin glasses (SG) are known as a prototype of many complex systems. The study began with a discovery of the canonical SG materials. However, the theoretical analyses have not been so successful in explaining the experiments. There are many contradictory results among which many debates have been held. Consequently, there is a possibility of a critical line, which is a main topic of this grant. We developed several new methods to overcome the difficulties in numerical simulations. We performed gigantically large simulations, collected very precise data and reached the following conclusions.
(1)The +-J Heisenberg SG model can explain the canonical SG experiment including values of critical exponents. (2) Numerical simulations with small sizes are plagued by the size crossover, which is an origin of many contradictions. (3) Critical lines are observed due to insufficient data precisions.
New methods developed in this grant will be applicable to many complex systems, and are very promising.

Report

(4 results)
  • 2014 Annual Research Report   Final Research Report ( PDF )
  • 2013 Research-status Report
  • 2012 Research-status Report
  • Research Products

    (6 results)

All 2015 2014 2013 2012

All Journal Article (1 results) (of which Peer Reviewed: 1 results,  Acknowledgement Compliant: 1 results) Presentation (5 results)

  • [Journal Article] Window Measurements of Simulations in Random Systems2015

    • Author(s)
      Tota Nakamura
    • Journal Title

      Journal of the Physical Society of Japan

      Volume: 84

    • NAID

      40020325387

    • Related Report
      2014 Annual Research Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Presentation] 3次元ハイゼンベルグスピングラスのスピンカイラル相転移とボンド分布2015

    • Author(s)
      中村統太
    • Organizer
      日本物理学会第70回年次大会
    • Place of Presentation
      早稲田大学早稲田キャンパス
    • Year and Date
      2015-03-24
    • Related Report
      2014 Annual Research Report
  • [Presentation] ベイズ推定を用いた相関長評価法2014

    • Author(s)
      中村統太
    • Organizer
      日本物理学会2014年秋季大会
    • Place of Presentation
      中部大学春日井キャンパス
    • Year and Date
      2014-09-10
    • Related Report
      2014 Annual Research Report
  • [Presentation] 3次元ハイゼンベルグスピングラスのスピンカイラル転移2014

    • Author(s)
      中村統太
    • Organizer
      日本物理学会2014年秋季大会
    • Place of Presentation
      中部大学春日井キャンパス
    • Year and Date
      2014-09-07
    • Related Report
      2014 Annual Research Report
  • [Presentation] 3次元ハイゼンベルグスピングラスのWindow測定と相関長スケーリング2013

    • Author(s)
      中村統太
    • Organizer
      日本物理学会
    • Place of Presentation
      徳島大学常三島キャンパス
    • Related Report
      2013 Research-status Report
  • [Presentation] 3次元ハイゼンベルグスピングラス模型の動的相関長スケーリング2012

    • Author(s)
      中村統太
    • Organizer
      日本物理学会2012年秋季大会
    • Place of Presentation
      横浜国立大学
    • Related Report
      2012 Research-status Report

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Published: 2013-05-31   Modified: 2019-07-29  

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