Probing Superconducting Fluctuations on Mesoscopic Scales: Conductance Fluctuations and Oscillations, and Electron Tunneling

非技术性电子产品迅速微型化到亚微米尺度，从而大大提高了计算机的能力，这是过去几十年来科学、技术和经济进步的驱动力。这场信息技术革命的基础是我们对电子如何在固态材料中传导的理解。该项目的目标是进一步将电子传导的实验研究扩展到纳米尺寸的样品和器件元件。该项目将在这些样品中寻找奇异的电导波动和振荡，这将影响我们对纳米尺度上电子输运的理解。该项目还将研究通过“自上而下”的电子束光刻和“自下而上”的模板纳米纤维相结合来制造和集成纳米尺寸器件元件的独特方法。其目标是为下一代电子器件寻找新材料、新物理原理和新制造技术。除了培养博士后和研究生外，该项目还将吸引本科生（目前支持一名）和来自代表性不足群体的学生（目前支持一名）从事尖端科学研究。这将有助于增加打算从事教学和研究工作的研究生人数，这对保持我国科学技术的活力至关重要。技术本项目将研究金属和超导薄膜、纳米线和纳米管的相关效应。这些介观或纳米尺寸的样品通过基于电子束光刻的“自上而下”方法或基于模板纳米纤维的“自下而上”方法或两者的组合来制造。传输和隧道实验将进行探测电导波动，振荡，和约瑟夫森隧道在这些样品。这些实验将揭示关联和局域化在超导体-绝缘体量子相变中的重要作用。这些实验也将寻找电导波动和振荡行为的金属（或超导）纳米管的直径显着小于声子退相长度（或金兹伯格朗道相干长度），并在薄膜以上的自旋顺磁限制。在这项研究中开发的纳米纤维方法将影响纳米科学和技术的新兴领域。除了培训博士后和研究生外，该项目还将吸引本科生（目前支持一名）和来自代表性不足群体的学生（目前支持一名）从事尖端研究。这些努力将有助于增加打算从事教学和研究工作的研究生人数，这对保持这个国家的科学和技术活力至关重要。

Non TechnicalThe rapid miniaturization of electronics to the sub-micrometer scale and the resulting vast increase in the capability of computers has been a driving engine for scientific, technological, and economic progress in the past few decades. The foundation of this revolution in information technology is our understanding of how electrons conduct in solid state materials. The goal of this project is to further extend the experimental investigation of electron conduction to nano-sized samples and device elements. This project will search for exotic conductance fluctuations and oscillations in such samples, which will impact on our understanding of electron transport on nanosized length scales. This project will also investigate unique methods for the fabrication and integration of nanosized device elements by a combination of "top-down" electron-beam lithography and "bottom-up" template nanofabrication. The goal is to search for new materials, new physical principles, and new fabrication techniques for the next generation of electronic devices. In addition to training post-docs and graduate students, this project will attract undergraduates (one currently supported) and students from under-represented groups (one currently supported) to pursue cutting-edge scientific research. Such efforts will help to increase the number of graduate students who intend to pursue teaching and research careers, which is critically important for maintaining the vitality of science and technology of this nation.Technical This project will investigate correlation effects in metallic and superconducting ultrathin films, nanowires, and nanotubes. These mesoscopic or nanosized samples are fabricated by either a "top-down" approach based on electron-beam lithography, or a "bottom-up" approach based on template nanofabrication, or a combination of the two. Transport and tunneling experiments will be performed to probe conductance fluctuations, oscillations, and the Josephson tunneling in these samples. These experiments will reveal the important roles that correlation and localization play in the superconductor-insulator quantum phase transition. These experiments will also search for conductance fluctuation and oscillation behavior in metallic (or superconducting) nanotubes of diameters significantly smaller than the phonon dephasing length (or the Ginzburg-Landau coherence length), and in thin films above the spin-paramagnetic limit. Nanofabrication methods developed in this research will impact on emerging fields of nano science and technology. In addition to training post-docs and graduate students, this project will attract undergraduates (one currently supported) and students from under-represented groups (one currently supported) to pursue cutting-edge research. Such efforts will help to increase the number of graduate students who intend to pursue teaching and research careers, which is critically important for maintaining the vitality of science and technology of this nation.