Topics in Statistical Physics

统计物理专题

• 批准号: 8719523
• 负责人: Daniel Fisher
• 金额: $ 20.78万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1990-07-01
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8719523&HistoricalAwards=false
• 关键词: Topics; Statistical; Physics

Many random magnetic systems are characterized by freezing and hysteretic behavior at low temperatures. The dynamics of spin glasses, random field systems, random interfaces, and other glassy systems will be investigated, using scaling and probabilistic renormalization group arguments, simplified models, and numerical calculations. The emphasis will be on the causes of the freezing and hysteretic phenomena and the interplay between equilibrium and non-equilibrium processes, such as decay of remanent magnetization and approach to equilibrium. In some disordered systems, transport processes are highly collective and non-liniar. Using sliding charge density waves as a paradigm, various cellective transport phenomena will be investigated, including flux flow in disordered superconductors and motion of interfaces between two fluids in a porous media. These systems do not move until a threshold driving force is reached, and near this threshold they exhibit novel non-linear dynamic critical phenomena. Below threshold, hysteretic behavior occurs which will also be investigated. Various quantum statistical phenomena will also be studied: spin wave dynamics in strongly quantum magnets, (such as solid 3He): scaling behavior near metal- insulator transitions; and the effects of dissipation on quantum phase transitions such as destruction of superconductivity in granular materials.

许多随机磁系统的特征是在低温下进行冷冻和滞后行为。 将研究自旋眼镜，随机场系统，随机界面和其他玻璃系统的动力学，使用缩放和概率的重态化组参数，简化模型和数值计算。重点将放在冰冻和滞后现象的原因上，以及平衡和非平衡过程之间的相互作用，例如remanent磁化和平衡方法的衰减。 在某些无序的系统中，运输过程是高度集体和非限制的。 将使用滑动电荷密度波作为范式，将研究各种细胞传输现象，包括无序超导体中的通量流以及多孔介质中两种流体之间接口的运动。 在达到阈值驱动力之前，这些系统不会移动，并且在此阈值附近，它们表现出了新型的非线性动态临界现象。 低于阈值，会发生滞后行为，也将进行研究。 还将研究各种量子统计现象：强量子磁体中的自旋波动力学（例如实心3HE）：金属绝缘子跃迁附近的缩放行为；以及耗散对量子相变的影响，例如破坏颗粒材料中的超导性。