Tunneling and Transport in Ordered and Disordered Superconductors

9303022戈德曼这项研究调查了在液氦温度下通过气相沉积在衬底上制备的无序超薄膜的性质。中心焦点是无序和磁场诱导的超导体-绝缘体转变。通过绘制磁场、温度和无序空间中的相图，通过确定临界指数，以及通过研究材料的输运和磁输运性质，可以确定这些转变背后的物理基础。薄膜的结构将通过反射高能电子衍射和扫描隧道显微镜进行原位研究。这些研究将提供有关薄膜成核和生长的信息。本研究主要研究超导材料薄膜的沉积、生长和物理性能。有趣的是，当施加磁场时，这些薄膜失去了超导性能，变成了电离体。这种电导率急剧变化的潜在物理机制还没有得到很好的理解，因此提出了一些测量方法来揭示这一现象的重要特征。这些结果将对超导科学产生根本性的影响。此外，研究人员还将研究薄膜的结构和成核，以了解材料的形态与观察到的性能之间的关系。***

9303022 Goldman This research investigates the properties of disordered ultrathin films prepared by vapor deposition onto substrates held at liquid helium temperatures. The central focus is on disorder and magnetic-field-induced superconductor-insulator transitions. The physics underlying these transitions will be identified by mapping out the phase diagram in the space of the magnetic field, temperature, and disorder, bu determining critical exponents, and by investigating the transport and magnetotransport properties of the materials. The structures of the films will be investigated in situ via reflection high energy electron diffraction, and scanning tunneling microscopy. These studies will provide information about the nucleation and growth of the films. %%% This research studies the deposition, growth and physical properties of thin films of superconducting materials. Interestingly, the films lose their superconducting properties when a magnetic field is applied to them, and become isulators. The underlying physics of this dramatic change in electrical conductivity is not well understood, and a number of measurements are proposed to reveal important characteristics of the phenomena. The results will be of fundamental interest in the science of superconductivity. Additionally, the workers will investigate the structure and nucleation of the films, to see how the materials morphology relates to the observed properties. ***