Non--Perturbative Interaction Effects in Disordered and Granular Metals

无序金属和颗粒金属中的非微扰相互作用效应

• 批准号: 0405212
• 负责人: Alex Kamenev
• 金额: --
• 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: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0405212&HistoricalAwards=false
• 关键词: Non; Perturbative; Interaction; Effects; Disordered

This award supports theoretical research and education in the area of strongly correlated electron materials. Electron-electron interactions have a dramatic effect on transport and thermodynamic properties of disordered systems. The effect is especially pronounced in systems with reduced dimensionality. While perturbative effects (taking place at relatively weak disorder and high temperature) are rather well understood, strongly disordered or low-temperature systems continue to be intellectually challenging for both experimentalists and theoreticians. The PI aims to address the twin problem of strong disorder and strong correlation with non-perturbative methods of quantum field theory. Instanton approaches have been fruitful for the study of the Coulomb blockade in quantum dots. In the first phase of the work, the PI will extend his Keldysh nonlinear sigma model approach to study granular arrays consisting of a large number of strongly connected dots (grains). The developed techniques will then be applied to generic disordered systems. The goal of the research is to describe reliably low-temperature properties of strongly disordered metals, including an apparent glassy behavior recently observed in experiments.Broader impacts of the award are primarily educational. Undergraduate students (including those participating in the NSF sponsored REU and summer-student programs) will be involved in the research activities. The project will also involve at least one full-time graduate student, who is expected to actively participate in directing undergraduate research. The upper level solid-state courses will directly benefit from the results of the research activity. This award will also facilitate interactions with the industry (seminars and possibly mini-courses are planned to be given for industrial researchers) as well as international collaboration with scientists from Germany, Israel, Japan and Russia. Results of the work will be disseminated broadly in scientific publications, national and international conferences and their proceedings. An additional venue of dissemination will be through graduate summer-schools, such as Les-Houches.%%%This award supports theoretical research and education to tackle the challenging problem of disordered materials with strongly correlated electrons. Correlations in the motion of electrons arise from strong interactions between electrons. While understanding strongly correlated materials with a regular arrangement of atoms is a challenging problem in and of itself, the combination of strong correlation and a disordered configuration of atoms is a very difficult problem. The PI will use advanced methods of theoretical condensed matter physics to attack this problem starting from a consideration of granular systems. Experiments have revealed interesting and poorly understood phenomena in disordered and strongly correlated systems. The understanding of these may provide the key to understanding apparent experimental observations of a metallic state thought not to occur in disordered two-dimensional systems and an apparent glassy behavior recently observed in a number of experiments. Broader impacts of the award are primarily educational. Undergraduate students (including those participating in the NSF sponsored REU and summer-student programs) will be involved in the research activities. The project will also involve at least one full-time graduate student, who is expected to actively participate in directing undergraduate research. The upper level solid-state courses will directly benefit from the results of the research activity. This award will also facilitate interactions with the industry (seminars and possibly mini-courses are planned to be given for industrial researchers) as well as international collaboration with scientists from Germany, Israel, Japan and Russia. Results of the work will be disseminated broadly in scientific publications, national and international conferences and their proceedings. An additional venue of dissemination will be through graduate summer-schools, such as Les-Houches.***

该奖项支持强相关电子材料领域的理论研究和教育。电子-电子相互作用对无序系统的输运和热力学性质具有巨大影响。这种效应在降维系统中尤其明显。虽然微扰效应（在相对较弱的无序和高温下发生）已被很好地理解，但强烈无序或低温系统对实验学家和理论家来说仍然是智力上的挑战。该PI旨在通过量子场论的非微扰方法解决强无序性和强相关性的孪生问题。瞬子方法对于量子点库仑封锁的研究取得了丰硕的成果。在工作的第一阶段，PI 将扩展他的 Keldysh 非线性 sigma 模型方法来研究由大量强连接点（颗粒）组成的颗粒阵列。然后开发的技术将应用于通用无序系统。该研究的目标是描述强无序金属的可靠低温特性，包括最近在实验中观察到的明显玻璃态行为。该奖项的更广泛影响主要是教育性的。本科生（包括参加 NSF 资助的 REU 和暑期学生项目的学生）将参与研究活动。该项目还将涉及至少一名全日制研究生，预计他将积极参与指导本科生研究。高级固态课程将直接受益于研究活动的成果。该奖项还将促进与行业的互动（计划为行业研究人员举办研讨会和可能的迷你课程）以及与德国、以色列、日本和俄罗斯科学家的国际合作。工作成果将在科学出版物、国内和国际会议及其会议记录中广泛传播。另一个传播场所将通过研究生暑期学校，例如 Les-Houches。%%%该奖项支持理论研究和教育，以解决具有强相关电子的无序材料的挑战性问题。电子运动的相关性源于电子之间的强相互作用。虽然理解具有规则原子排列的强相关材料本身就是一个具有挑战性的问题，但强相关性和原子无序排列的结合是一个非常困难的问题。 PI 将使用理论凝聚态物理的先进方法从粒状系统的考虑出发来解决这个问题。实验揭示了无序和强相关系统中有趣且鲜为人知的现象。对这些的理解可能为理解金属态的明显实验观察提供了关键，该金属态被认为不会出现在无序二维系统中，并且最近在许多实验中观察到了明显的玻璃态行为。 该奖项的更广泛影响主要是教育方面的。本科生（包括参加 NSF 资助的 REU 和暑期学生项目的学生）将参与研究活动。该项目还将涉及至少一名全日制研究生，预计他将积极参与指导本科生研究。高级固态课程将直接受益于研究活动的成果。该奖项还将促进与行业的互动（计划为行业研究人员举办研讨会和可能的迷你课程）以及与德国、以色列、日本和俄罗斯科学家的国际合作。工作成果将在科学出版物、国内和国际会议及其会议记录中广泛传播。另一个传播场所将是通过研究生暑期学校，例如 Les-Houches。***