Defect Dynamics and Quantum Transport in Disordered Mesoscopic Metals

无序介观金属中的缺陷动力学和量子输运

• 批准号: 9321850
• 负责人: Norman Birge
• 金额: $ 27万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-04-15 至 1997-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9321850&HistoricalAwards=false
• 关键词: Defect; Dynamics; Quantum; Transport; Disordered

9321850 Birge Technical abstract: The low temperature electrical properties of mesoscopic metal samples will be studied in order to uncover new physical phenomena that are unique to the mesoscopic regime. The specific problems to be studied include dissipative quantum tunneling of single defects in disordered metals, modulation of microscopic defect properties by externally applied electric and strain fields, and the role of mesoscopic superconductors in enhancing electronic quantum phase coherence. Measurements of 1/f noise in larger samples complement the mesoscopic measurements by providing statistical information about defects in disordered systems. Non-technical abstract: This proposal focuses on two areas of study related to disordered metals. The first is the study of individual, atomic defects. By carefully measuring the electrical conductance of sub micrometer samples, one can detect the motion of a single atom within the sample. This type of study reveals details about individual defects that are not obtainable from studies of larger samples. The second area of study is the quantum-mechanical behavior of electrons in metals at low temperature. Due to their wave-like nature, electrons in metals exhibit interference. In sub micrometer samples of normal and superconducting materials, this interference leads to a number of new, intriguing electrical properties. These effects can have potential impact on the development of future mesoscopic devices. ***

小行星9321850 技术摘要：将研究介观金属样品的低温电学性质，以揭示介观制度所特有的新物理现象。 要研究的具体问题包括无序金属中单个缺陷的耗散量子隧穿，外部施加的电场和应变场对微观缺陷性质的调制，以及介观超导体在增强电子量子相位相干性中的作用。 在较大的样品中的1/f噪声的测量补充介观测量提供有关无序系统中的缺陷的统计信息。 非技术摘要：该提案侧重于与无序金属相关的两个研究领域。 第一个是研究单个的原子缺陷。 通过仔细测量亚微米样品的电导率，可以检测样品中单个原子的运动。 这种类型的研究揭示了无法从较大样本研究中获得的单个缺陷的详细信息。 第二个研究领域是低温下金属中电子的量子力学行为。 由于它们的波动性质，金属中的电子表现出干涉。 在正常和超导材料的亚微米样品中，这种干扰导致了许多新的，有趣的电学性质。 这些效应可能对未来介观器件的发展产生潜在的影响。 ***