Nonequilibrium Dynamics of Disordered Condensed Matter Systems

9730678 Marchetti将进行理论研究，目的是了解各种空间扩展凝聚态系统的动力学性质。研究的重点是无序驱动的周期性介质的非平衡动力学。这类系统的例子包括ii型超导体中的磁通晶格、各向异性导体中的电荷密度波和二维电子气体中的磁致维格纳晶体。正如最近的实验所揭示的那样，相互作用、无序和驱动的相互作用导致了一种复杂的动力学，人们对这种动力学知之甚少。这项工作的主要目标是为描述这些非平衡系统建立一个理论框架，并绘制出它们的非平衡相图。密切相关的问题也将在摩擦和润滑的微观模型中进行研究。一个重要的区别是，惯性项在过阻尼系统中可以忽略不计，如通量格，在这种情况下可能很重要，并改变滑动状态的性质。一个关键的目标是了解表面粗糙度和体弹性在屈服耗散中的相对重要性。另一项更直接的工作是继续过去对ii型超导体磁通线阵列的研究。重点是纠缠和纵向相关的物理后果，这是通过磁化测量和输运实验来探索的。本文描述了两种流体力学的解析工作，旨在描述流体的纠缠和非纠缠组分，以及解决横向迈斯纳效应对点无序的稳定性的数值工作。将对描述高温超导体行为的一类问题进行理论研究。这类问题非常普遍，其结果也将影响摩擦、周期性介质中的电荷输运和低温下新相的研究。＊＊＊

9730678 Marchetti Theoretical research will be conducted with the goal of understanding the dynamical properties of various spatially extended condensed matter systems. A major part of the research focusses on the nonequilibrium dynamics of periodic media driven through disorder. Examples of such systems include flux lattices in type-II superconductors, charge density waves in anisotropic conductors and the magnetically- induced Wigner crystal in a two-dimensional electron gas. As revealed by recent experiments, the interplay of interaction, disorder and drive results in a complex dynamics that is poorly understood. The main goals of this work are to develop a theoretical framework for the description of these nonequilibrium systems and to map out their nonequilibrium phase diagrams. Closely related problems that will also be investigated arise in microscopic models of friction and lubrication. One important difference is that inertial terms, negligible for overdamped systems such as flux lattices, may be important in this case and change the nature of the sliding state. A key objective is to understand the relative importance of surface roughness and bulk elasticity in yielding dissipation. Another effort more directly continues past research on flux- line arrays in type-II superconductors. The focus is on the physical consequences of entanglement and longtudinal correlations which are probed experimentally by magnetization measurements and transport experiments. Both analytical work, aiming at a two-fluid hydrodynamics capable of describing both entangled and disentangled components of flux liquid, and numerical work, addressing the stability of the transverse Meissner effect against point disorder, are described. %%% Theoretical research will be conducted on a class of problems which describe the behavior of the high temperature superconductors. These type of problems are very common and the results will also impact studies of friction, charge transport in periodic media and novel phases at low temperatues. ***