Dynamics of Vortices and Interfaces in Condensed Matter Systems

该奖项支持对高温超导体和量子霍尔效应系统中的涡流和界面的研究和教育。PI旨在阐明这些缺陷如何在响应外力（如输运电流和热梯度）时移动和波动，以及移动缺陷如何产生于微观自由度并与之相互作用。拟议的工作有两个重点。首先，金兹堡-朗道理论及其推广将用于研究d波超导体中涡旋晶格的熔化和单涡旋的动力学。铜超导体中赝隙形成的某些方面将使用准粒子与相位波动（以热激活涡-反涡对的形式）相互作用的模型进行研究。第二个推力涉及高温超导体和量子霍尔系统的界面动力学研究。磁通通常以磁枝晶的形式进入超导薄膜，在超导薄膜中，涡旋液相与磁化强度相反的迈斯纳相或涡旋相之间存在明显的边界。PI计划研究热效应在产生分离两相的界面不稳定性中的作用。受二维量子霍尔系统在更高朗道能级中令人惊讶的电阻率异常的激励，PI计划利用PI的二维电子液体形状波动的轮廓动力学形式，为中等磁场中的二维电子气体开发一个电子“smectic”模型。这种方法的一个目的是对该模型可能的低温阶段进行定性理解。该奖项支持理论凝聚态物理两个领域的基本问题的研究和教育：高温超导体中的涡流和量子霍尔液体中的界面。前者对于理解超导态的耗散机制很重要。后者试图探索在高磁场下二维电子气体中出现一种新的各向异性多电子态的可能性。这种空间非均匀的量子霍尔态或“条纹相”可能自发地发生在两种半导体材料（如GaAs和GaAlAs）之间的界面上的电子气体中。

9978547DorseyThis award supports research and education on vortices and interfaces in high temperature superconductors and quantum Hall effect systems. The PI seeks to elucidate how these defects move and fluctuate in response to external forces, such as transport currents and thermal gradients, and how moving defects arise from and interact with microscopic degrees of freedom. There are two thrusts to the proposed work. In the first, Ginzburg-Landau theory and its generalizations will be used to study the melting of the vortex lattice and the dynamics of a single vortex in a 'd-wave' superconductor. Some aspects of psuedogap formation in the cuprate superconductors will be studied using a model in which quasiparticles interact with phase fluctuations (in the form of thermally activated vortex-antivortex pairs). The second thrust involves the study of interface dynamics in high temperature superconductors and quantum Hall systems. Magnetic flux often enters a thin superconducting film in the form of magnetic dendrites, in which there is a sharp boundary between a vortex liquid phase and either the Meissner phase or vortex phase with opposing magnetization. The PI plans to study the role of thermal effects in producing instabilities of the interface separating the two phases. Motivated by the surprising resistivity anomaly in two-dimensional quantum Hall systems in higher Landau levels, the PI plans to develop an electron "smectic" model for the two-dimensional electron gas in moderate magnetic fields using the PI's contour dynamics formalism for shape fluctuations in two-dimensional electron liquids. An aim of this approach is a qualitative understanding of the possible low-temperature phases of this model. This award supports research and education in fundamental problems in two areas of theoretical condensed matter physics: vortices in the high temperature superconductors and interfaces in quantum Hall liquids. The former are important in understanding dissipation mechanisms in the superconducting state. The latter seeks to explore the possibility that a novel anisotropic many-electron state occurs in a two-dimensional gas of electrons in a high magnetic field. This spatially inhomogeneous quantum Hall state or 'striped phase' might spontaneously occur in an electron gas at an interface between two semiconducting materials like GaAs and GaAlAs with a large applied magnetic field.