| Project/Area Number |
16540341
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Mathematical physics/Fundamental condensed matter physics
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| Research Institution | Osaka University |
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Principal Investigator |
KAWAMURA Hikaru Osaka University, Graduate School of Science, Professor, 大学院・理学研究科, 教授 (30153018)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2004: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | frustration / spin glass / chirality / pyrochlore / spin-chirality decoupling / chiral glass / スピン-カイライリティ分離 / モンテカルロシミュレーション / レプリカ対称性の破れ |
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| Research Abstract |
Magnetic ordering and slow dynamics of frustrated magnets have been studied theoretically and numerically mainly for spin glasses. Particular attention was paid to the "chirality", a quantity of recent theoretical and experimental interest. We examined whether the peculiar behavior of the "spin-chirality decoupling" proposed recently really occurred or not, as well as various off-equilibrium phenomena induced by the chirality such as the violation of the fluctuation-dissipation relation. We performed a large scale Monte Carlo simulation of the 3D Heisenberg Edward-Anderson model, and have revealed the existence of a finite-temperature chiral-glass transition and of the spin-chirality decoupling phenomenon at long length and time scales, as predicted by the present author. It was also found that the peculiar one-step-like replica-symmetry breaking (RSB) occurred in the chiral-glass ordered state. In magnetic fields, this RSB gives rise to a thermodynamic SQ transition even in fields, which consistently explains the long-standing experimental puzzle for the in-field behavior of canonical spin glasses. The peculiar RSB pattern was indeed observed by means of off-equilibrium simulations of spin glasses via the violation of the fluctuation-dissipation theorem.
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