Dynamics of Vortices and Interfaces in Condensed Matter Systems

9978547 Dorsey该奖项支持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移动和波动响应外力，如运输电流和热梯度，以及如何移动缺陷产生的微观自由度和相互作用。拟议的工作有两个重点。 首先，我们将利用金-朗道理论及其推广来研究d波超导体中涡旋晶格的熔化和单个涡旋的动力学。 在铜氧化物超导体的psuedogap形成的一些方面将使用一个模型，其中准粒子相互作用的相位波动（在热激活的涡旋-antivortex对的形式）进行研究。第二个重点是高温超导体和量子霍尔系统的界面动力学研究。 磁通量通常以磁枝晶的形式进入薄超导膜，其中涡旋液相与具有相反磁化的迈斯纳相或涡旋相之间存在尖锐的边界。 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。 由于在较高的朗道能级上二维量子霍尔系统中令人惊讶的电阻率异常，PI计划使用PI的二维电子液体形状波动的轮廓动力学形式主义，在中等磁场中为二维电子气开发一个电子“近晶”模型。 这种方法的一个目的是定性地了解该模型可能的低温阶段。该奖项支持理论凝聚态物理学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。 前者对于理解超导状态下的耗散机制很重要。后者试图探索一种新的各向异性多电子态发生在一个高磁场中的二维电子气体的可能性。这种空间不均匀的量子霍尔态或“条纹相”可能会自发地发生在两种半导体材料（如GaAs和GaAlAs）之间的界面处的电子气中，并具有较大的外加磁场。

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.