Topics in Statistical Physics

许多随机磁系统在低温下具有冻结和滞后行为。自旋玻璃、随机场系统、随机界面和其他玻璃系统的动力学将被研究，使用标度和概率重整化群参数、简化模型和数值计算。重点讨论冻结和滞后现象的原因以及平衡和非平衡过程之间的相互作用，如剩余磁化强度的衰减和接近平衡。在一些无序系统中，传输过程是高度集体性和非线性的。以滑动电荷密度波为范型，研究了无序超导体中的磁通流动和多孔介质中两种流体之间的界面运动等各种电荷输运现象。在达到阈值驱动力之前，这些系统不会运动，并且在这个阈值附近，它们表现出新颖的非线性动态临界现象。在阈值以下，发生滞回行为，也将进行调查。各种量子统计现象也将被研究：强量子磁体(如固体3He)中的自旋波动力学；金属-绝缘体转变附近的标度行为；以及耗散对量子相变的影响，如颗粒材料中超导电性的破坏。

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.