Tunneling and Transport in Ordered and Disordered Superconductors

有序和无序超导体中的隧道效应和输运

• 批准号: 9303022
• 负责人: Allen Goldman
• 金额: $ 38.5万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 1997-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9303022&HistoricalAwards=false
• 关键词: Tunneling; Transport; Ordered; Disordered; Superconductors

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. ***

9303022高盛这项研究研究了通过蒸气沉积制备的无序超薄膜的特性，这些薄膜在液态氦气温度下固定的底物上。 中心重点是障碍和磁场诱导的超导体 - 绝缘体转变。 这些过渡为基础的物理学将通过在磁场，温度和无序的空间中绘制相图，确定关键指数，并研究材料的传输和磁转移特性，来识别这些过渡的物理。 膜的结构将通过反射高能电子衍射和扫描隧道显微镜原位研究。 这些研究将提供有关膜的成核和生长的信息。 %%％％研究研究了超导材料的薄膜的沉积，生长和物理特性。 有趣的是，当将磁场施加到它们并成为iSulators时，膜将失去其超导性能。 这种急剧导电性变化的基本物理学尚不清楚，并提出了许多测量以揭示现象的重要特征。 结果将具有超导科学的基本兴趣。 此外，工人将研究膜的结构和成核，以了解材料形态与观察到的特性的关系。 ***