Physical Phenomena in Superconducting Arrays, High-Tc Superconductors, and Composite Media

将在三个研究领域进行9731511项斯特劳德理论研究。第一个涉及对超导阵列特性的研究。将通过数值和分析技术来研究在何种情况下可以使这些阵列相干振荡。还计划进行额外的计算，以处理涡旋运动、量子效应、通量噪声和交流。磁化率、经典磁阻和这种阵列中的长程相互作用，使用各种理论技术。第二个领域是磁通晶格熔化及相关现象的理论研究，主要是在高温超导体中。一个先前发展的最低朗道能级表示将被扩展到处理存在无序的熔剂晶格熔化，并研究有无序和无无序的c轴约瑟夫森等离子体在熔剂液态中的行为。磁通晶格熔化的进一步计算计划在均匀受挫的XY模型和分层的伦敦模型中进行，包括有钉扎和没有钉扎。作为一个推测项目，将研究将这些方法扩展到层状磁性材料的可能性。最后，我们将研究经典非均匀材料物理学的几个方面。重点将放在这类材料的非线性光学响应和线性交流。各向异性材料(如准一维导电聚合物)的多晶响应。它还计划研究将无序二维超导体作为经典电磁波混沌传播的模型系统的可能性。将使用数值和分析技术在三个研究领域进行理论研究。这三个领域是超导阵列的研究；磁通晶格熔化；以及经典的非均匀材料。前两个领域因其对高温超导体的适用性而受到越来越多的关注。第三个领域是设计具有独特(光学)性能的复合材料。***

9731511 Stroud Theoretical studies will be conducted in three areas of research. The first involves the study of the properties of superconducting arrays. The circumstances under which these arrays can be made to oscillate coherently will be studied by both numerical and analytical techniques. Additional calculations are planned to treat vortex motion, quantum effects, flux noise, a.c. magnetic susceptibility, classical magnetoresistance, and long-range interactions in such arrays, using a variety of theoretical techniques. The second area is a theoretical investigation of flux lattice melting and related phenomena, primarily in high temperature superconductors. A previously developed lowest-Landau level representation will be extended to treat flux lattice melting in the presence of disorder, and to study the behavior of the c-axis Josephson plasmon in the flux liquid state, both with and without disorder. Further calculations of flux lattice melting are planned in a uniformly frustrated XY model and a layered London model, both with and without pinning. As a speculative project, the possibility of extending these approaches to layered magnetic materials will be investigated. Finally, several aspects of the physics of classically inhomogeneous materials will be studied. The emphasis will be on the nonlinear optical response of such materials, and on the linear a.c. response of polycrystals of anisotropic materials (such as quasi-one-dimensional conducting polymers). It is also planned to examine the possibility of treating a disordered two-dimensional superconductor as a model system for chaotic propagation of classical electromagnetic waves. %%% Theoretical research will be conducted in three areas of research using numerical and analytical techniques. These three areas are the study of superconducting arrays; flux lattice melting; and classical inhomogeneous materials. The first two areas are ones which have received increased attention due t o their applicability to the high temperature superconductors. The third area is one of great interest in designing composite materials with unique (optical) properties. ***