Magnetic ordering and slow dynamics of frustrated systems

受挫系统的磁排序和缓慢动态

• 批准号: 16540341
• 负责人: KAWAMURA Hikaru
• 金额: $ 2.3万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16540341/
• 关键词: 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

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.

本文主要对自旋玻璃的磁性有序和慢动力学进行了理论和数值研究。特别注意的是“手性”，一个最近的理论和实验的兴趣量。我们研究了最近提出的“自旋-手性解耦”的特殊行为是否真的发生，以及手性引起的各种不平衡现象，如涨落-耗散关系的破坏。我们对三维Heisenberg - Edward-Anderson模型进行了大规模蒙特卡罗模拟，并揭示了在长长度和时间尺度上存在有限温度的手性-玻璃化转变和自旋-手性解耦现象，正如作者所预测的那样。在手性玻璃有序态中还发现了一种特殊的一步式复制对称破缺（RSB）。在磁场中，这种RSB即使在场中也会引起热力学SQ跃迁，这一致地解释了规范自旋玻璃场内行为的长期实验难题。通过违反涨落耗散定理对自旋玻璃进行非平衡模拟，确实观察到了这种特殊的RSB模式。

项目成果

Replica symmetry breaking transition of the weakly anisotropic Heisenberg spin glasses inmagnetic fields

弱各向异性海森堡自旋玻璃在磁场中的复制对称破缺转变

• 发表时间: 2004
• 期刊: Phys.Rev.Letters 92
• 作者: Daisuke Imagawa;Hikaru Kawamura
• 通讯作者: Hikaru Kawamura

Exact Analysis Based on Gauge Transformation in Spin-Glass Research

旋转玻璃研究中基于规范变换的精确分析

• 发表时间: 2005
• 期刊: JPSJ Online-News and Comments Jan.15
• 作者: Koji Hukushima;Hikaru Kawamura;Hikaru Kawamura
• 通讯作者: Hikaru Kawamura

Correlation length of the Heisenberg ferromagnet in 2 and 3 dimensions

海森堡铁磁体在 2 维和 3 维中的相关长度

• 发表时间: 2005
• 期刊: Frontiers of Basic Science
• 作者: D.X.Viet;H.Kawamura
• 通讯作者: H.Kawamura

Numerical studies of the ordering of the ± J XY spin-glass ladder

± J XY 自旋玻璃梯排序的数值研究

• 发表时间: 2005
• 期刊: Phys. Rev. B 72
• 作者: Tsukasa Uda;Hajime Yoshino;Hikaru Kawamura
• 通讯作者: Hikaru Kawamura

Replica symmetry breaking transition of the weakly anisotropic Heisenberg sping glasses in magnetic fields

弱各向异性海森堡斯宾格玻璃在磁场中的复制对称破缺转变

• 发表时间: 2004
• 期刊: Phys.Rev.Letters 92
• 作者: Daisuke Imagawa;Hikaru Kawamura
• 通讯作者: Hikaru Kawamura