Hierarchy, Dynamics and Memory Phenomena of Metastable States in Random Systems

随机系统亚稳态的层次结构、动力学和记忆现象

• 批准号: 62540262
• 负责人: HAJIME TAKAYAMA
• 金额: $ 1.22万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1988
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62540262/
• 关键词: Mean-Field Theory of Spin Glasses; Ultrametricity of Metastable States; Re-entrant Transition; Naive Mean-Field Model; Nonlinear Dynamical System with Randomness; Mode-Locking Phenomena; Noises in CDW Current; CDW電流の確率的な振舞い; 自由エネルギーの多谷構造; ナイーブ平均場

In a random system with frustrations in its interactions there exist a number of metastable states, and its free energy seen in a certain phase space has complicated multi-valley structure. In this project we aimed to get deeper understandings on hierarchical structure of such metastable states, and on dynamics and memory phenomena associated with them. For this purpose we have analyzed in detail a few mean-field models for spin glasses. A charge-density-wave (CDW) system in quasi one-dimensional conductors exhibits a variety of electric conduction phenomena. We have also tried to understand them in a unified way from the view-point that the CDW is a nonlinear dynamical system with spin-glass-like randomness. The analyses here are based on the Fukuyama-Lee-Rice (FLR) model, in which the CDW is regarded as a continuum obeying classical mechanics. The following points are clarified in this project.1. Mean-Field Models of Spin Glasses:(1) The free energy structure of the SK model is in fa … More ct ultrametric, and the relaxation of a state by thermally activated processes obeys the stretched exponential law. (2) A proper extension of the sk model in such a way as to extract characteristic features of the interactions in each material is able to explain spin-glass phenomena, such as the re-entrant transition, of the material in certain detail. (3) The spin-glass picture derived on the SK model holds true also on the 'naive' mean-field model, in which Onsager's reaction field in the SK model is discarded.2. CDW Dynamics:(1) The nonlinear conductivity of the FLR model exhibits characteristic dependence on the dimensionality of the system. Its 3d behavior is compatible with experimental results. (2)Mode-locking phenomena in the CDW system can be interpreted as cooperative ones induced by the external ac field. (3) When the heat-bath effect is included, the stochastic behavior of the CDW current in the FLR model corresponds qualitatively to the recently observed results on the width of the narrow-band-noise peak and on the 1/f-type broad-band-noise. These phenomena are considered to originate from the stochastic transition of the system between many sliding configurations of the CDW which are close to a stationary one. Less

在其相互作用中有挫败感的随机系统中，存在于该项目中的自由能，请参见该项目的自由度。与它们相关的目的。统一的方式从视图中cdw是一种类似的随机性。在这个项目中。1。提取物质中的相互作用的特征可以解释某些细节的旋转玻璃现象，例如重点转变。 - 在SK模型中，Onsager的反应场是动力学：（1）FLR模型的非线性电导率表现出对系统的特征性依赖性。在FLR模型中，通过热浴的效应将CDW电流定为定性，以对应于窄带 - 噪声峰的宽度和1/F型宽频段噪声上的宽度。从CDW的任何滑动配置的随机过渡中，它们接近固定型

项目成果

Masakatsu ISHIKAWA.: Prog.Theor.Phys.79. 359-372 (1988)

石川正胜：Prog.Theor.Phys.79。

Hiroshi MATSUKAWA.: J.Phys.Soc.Jpn.57. 3463-3473 (1988)

松川浩：J.Phys.Soc.Jpn.57。

Hiroshi MATSUKAWA: J.Phys.Soc.Jpn.57. 3463-3473 (1988)

松川浩：J.Phys.Soc.Jpn.57。

Hiroshi MATSUKAWA: Proc. 18th Int. Conf. on Low Temp. Phys., Kyoto, 1987 Jpn. J. Appl. Phys.26 Suppl.601-602 (1987)

松川浩：Proc。

Masakatsu ISHIKAWA: "On the Phase Dynamics of One-Dimensional Incommensurate Charge-Density-Wave in an Electric Field" Prog. Theor. Phys.79. 359-372 (1988)

Masakatsu ISHIKAWA：“电场中一维不相称电荷密度波的相位动力学”Prog。