Fundamental Experimental Properties of Mesoscopic Systems

这是一个凝聚态物理项目，研究电子通过亚微米导体传输的量子力学特性。在这些非常小的结构中，电子波函数的波长的相位是通过各种微妙的实验安排来探测的重要变量。本项目将在比相相干时间短得多和长得多的时间尺度上系统地探索介观系统的相相干输运特性。最先进的直流超导量子干涉装置（squid）将被用于研究单金属环和金属环阵列的磁响应的尺寸依赖性。目标是理解为什么相位相干环路中的持续电流似乎具有比预期大几个数量级的量子涨落。此外，还将研究尺寸接近近藤筛分长度的介观体系的磁性和输运性质。该项目为研究生和博士后提供了良好的教育机会。他们参与了凝聚态物理前沿的智力挑战研究。这些实验需要最新的制作和测量方法，并为学生从事广泛的科学或技术职业做好准备。这是一个凝聚态物理项目，采用最先进的微加工方法来制备超小型结构。大部分工作都集中在理解电子如何在纳米级结构中流动。传统的电流概念并不适用，电子的波动力学特性决定了回路、回路阵列、薄膜等中电流的响应。该项目解决了目前在纳米结构的量子力学行为中尚未解决的问题。这些问题与微电子工业有关，在微电子工业中，晶体管的尺寸正在稳步减小到所谓的介观领域，在介观领域中，量子力学变得很重要。另一个项目涉及含有磁性杂质原子的纳米线的性质。杂质对电子传递的影响令人惊讶，但人们对其了解甚少。该项目为研究生和博士后提供了良好的教育机会。他们参与了凝聚态物理前沿的智力挑战研究。这些实验需要最新的制作和测量方法，并为学生从事广泛的科学或技术职业做好准备。＊＊＊

9730577 Webb This is a condensed matter physics project that investigates the quantum mechanical properties of electron transport through submicron conductors. In these very small structures the phase of the wavelength of the electron wave function are important variables that are probed by a variety of subtle experimental arrangements. The project will systematically explore the phase coherent transport properties of mesoscopic system on time scales much shorter and much longer than the phase coherence time. State- of-the-art dc superconducting quantum interference devices (SQUIDs) will be used to study the size dependence of the magnetic response of both single and arrays of metal rings. The object is an understanding of why the persistent current in phase coherent loops appears to have quantum fluctuations which are orders of magnitude larger than expected. In addition, magnetic and transport properties of mesoscopic systems whose size approaches that of the Kondo screening length will be studied. The project provides exceptional educational opportunities for graduate students and post-doctoral associates. They are involved in intellectually challenging research at the frontiers of condensed matter physics. The experiments require the latest fabrication and measurement methods and prepare the students for a wide range of scientific or technical careers. %%% This is a condensed matter physics project that employs state-of- the-art micro-fabrication methods to prepare ultra-small structures. Much of the work is focused on understanding how electrons flow through the nanoscale structures. Conventional ideas of current flow do not apply, and the wave-mechanical properties of the electron dominate the response of currents in loops, arrays of loops, films, etc. The project addresses currently unsolved problems in the quantum mechanical behav ior of the nanostructures. These problems are relevant to those involved in the microelectronics industry where the size of transistors is steadily decreasing to the so-called mesoscopic realm where quantum mechanics becomes important. An additional project deals with the properties of nano-wires containing magnetic impurity atoms. The impurities influence the electron transport in surprising and poorly understood ways. The project provides exceptional educational opportunities for graduate students and post-doctoral associates. They are involved in intellectually challenging research at the frontiers of condensed matter physics. The experiments require the latest fabrication and measurement methods and prepare the students for a wide range of scientific or technical careers. ***