Theoretical Studies of Vortex Dynamics in Superconductors

9628926多尔西这项研究将集中在超导体中的涡旋动力学理论，这是一个具有重大科学和技术意义的领域。赠款的第一部分涉及旨在了解薄膜中涡旋动力学的项目。特别是，最近观察到，当一层薄的超导薄膜被置于足够强的磁场中时，磁场以“磁性树枝晶”的形式进入。为了理解这一现象，我们将在含时Ginzburg-Landau理论和超导涡旋的流体力学理论中研究涡旋液体与Meissner相之间的界面的传播和动态稳定性。第二部分研究了有序参数对称性对混合态涡旋动力学的影响；这项工作的动机是某些高温超导体中的有序参数可能具有d波特征。发展了d波超导体的含时Ginzburg-Landau理论，并将其用于研究混合态的纵向电导和霍尔电导以及能斯特效应。由于d波超导体的输运性质有一些超出这种描述的特征，我们将发展d波超导体的准经典格林函数技术。这些方法将被用来计算混合态的霍尔效应和能斯特效应，这两个量在高温超导体中表现出反常性质，并且没有得到一致的理论描述。将对高温超导体中形成的磁涡运动的各种问题进行理论研究。这些涡旋及其对磁场的响应在超导体的技术应用中非常重要。它们也具有巨大的根本利益。***

9628926 Dorsey This research will focus on the theory of vortex dynamics in superconductors, an area of great scientific and technological relevance. The first part of the grant involves projects aimed at understanding vortex dynamics in thin films. In particular, it has recently been observed that when a thin superconducting film is placed in a sufficiently strong magnetic field, the field enters in the form of "magnetic dendrites." To understand this phenomenon we will study the propagation and dynamic stability of interfaces between a vortex liquid and the Meissner phase, in both the time-dependent Ginzburg-Landau theory and a hydrodynamic theory of superconducting vortices. The second part of the grant is a study of the effect of order parameter symmetry on vortex dynamics in the mixed state; this work is motivated by the possibility that the order parameter in some of the high temperature superconductors may have a d-wave character. Time-dependent Ginzburg-Landau theories for d-wave superconductors will be developed and used to study the longitudinal and Hall conductivities, as well as the Nernst effect, in the mixed state. Since there are some features of the transport properties which are beyond this description, we will develop quasiclassical Green's function techniques for d-wave superconductors. These methods will be used to calculate the Hall effect and the Nernst effect in the mixed state, two quantities which have displayed anomalous properties in the high temperature superconductors and which have eluded a consistent theoretical description. %%% Theoretical research will be conducted on a variety of problems related to the motion of magnetic vortices which form in the high temperature superconductors. These vortices and their response to magnetic fields are important in technological applications of superconductors. They are also of great fundamental interest. ***