Studies of Two-Dimensional Superconductors and Multilayers in Magnetic Fields

小行星9508419 将进行广泛的实验，以便更好地了解全球温度与磁场相图，以及与二维和层状结构的各种相相关的动力学。 超导体，如 的 高温超导体 平均场线附近超导转变的热力学及其适用范围 的 最低Landau-Letel近似 对具有各种各向异性的多层膜进行了研究。 二维涡格融化的实验将集中在涡动力学中的不同交叉上 作为 的 长度 鳞片 是 被 即将呈现 超导体-绝缘体转变将通过系统地改变屏蔽程度和库仑势来研究。零场超流的性质与无序量的增加也将被调查。弱钉扎和强钉扎之间的区别将通过研究无序对电阻转变和涡旋动力学的作用来整理。 上述实验中的各种输运和磁性测量将提供多层膜的全局相图，这可能揭示新的玻璃相及其初始相关性。 高温超导体是层状材料，其中超导性发生在铜-氧平面中。 由于这种二维性，它们表现出特殊的性质。 本文研究了磁场中的电阻相变，以及涡旋结构和运动对磁致相变的影响。 能源 耗散 在 高 温度超导体和二维超导体 梗概.一个广泛的实验将进行一个模型系统中的铟锗/锗多层膜，其中PI的具有广泛的专业知识和控制和表征能力。这些实验一起将提供一个更好的理解的相图，以及与二维和层状超导体的各个阶段的动力学。 ***

9508419 Kapitulnik A wide range of experiments will be conducted in order to obtain a better understanding of the global Temperature vs. Magnetic field phase diagram, as well as the kinetics associated with various phases of two dimensional and layered superconductors such as the high-temperature superconductors. The thermodynamics of the superconducting transition near the mean-field line, and the range of validity of the Lowest-Landau-Letel approximation to multilayers with various anisotropy will be investigated. Experiments on the melting of the two-dimensional vortex lattice will focus on different crossovers in the vortex dynamics as the length scales are being tuned. Superconductor-insulator transitions will be studied by varying systematically the degrees of screening and the Coulomb potential. The nature of the zero-field superfluid transition with increasing amount of disorder will also be investigated. The difference between weak and strong pinning will be sorted out by studying the role of disorder on the resistive transition and vortex dynamics. The variety of transport and magnetic measurements in the above experiments will provide the global phase diagram of the multilayers, this may uncover new glass phases and their incipient correlation. %%% High temperature superconductors are layered materials where superconductivity occurs in the copper-oxygen planes. They exhibit peculiar properties due to this two-dimensionality. This proposal investigates the resistive transition in magnetic fields, and the role of vortex structure and motion causing energy dissipation in high temperature superconductors and two dimensional superconductors in general. A broad range of experiments will be conducted on a model system of molybdenum-germanium/germanium multilayer in which the PI's have extensive expertise and capabilities of co ntrol and characterization. These experiments together will provide a better understanding of the phase diagram as well as the kinetics associated with the various phases of two-dimensional and layered superconductors. ***