Nonequilibrium phenomena in strongly correlated systems

强相关系统中的非平衡现象

• 批准号: 1401908
• 负责人: Alex Levchenko
• 金额: $ 21.6万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2015-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1401908&HistoricalAwards=false
• 关键词: Nonequilibrium; phenomena; strongly; correlated; systems

NONTECHNICAL SUMMARY This award supports theoretical research and education on the properties of novel electronic states of matter that are driven out of the steady state of equilibrium. Recent advances in fabrication of materials and materials systems at the nanoscale, in materials science, and in experimental techniques have made it possible to investigate novel electronic systems and quantum mechanical phenomena with an unprecedented level of accuracy and control. When electrons are tightly spatially confined, their wave-like nature results in interference effects governed by quantum mechanics, and the interaction between the particles leads to a formation of novel strongly correlated states of electrons. These systems offer new conceptual scientific challenges and may be useful for a wide spectrum of future electronic technological applications. In close collaboration with experimental groups, the PI aims to investigate transport properties, for example how these systems conduct electricity, with an emphasis to discover new transport phenomena.Systems relevant to this investigation include Luttinger liquids, which are relevant to quantum wires which have a nanometer scale diameter and a micrometer scale length leading to an almost perfect one-dimensional environment for electrons. Electrons in semiconductor structures called quantum wells can be manipulated to form two-dimensional liquids, and if interactions are sufficiently strong the electrons may crystallize. The other relevant systems include recently discovered topological insulators, which are insulators in the bulk but almost perfect ideal conductors at the surface or edge of the sample. Superconductors are an important focus of the project. They display vanishing resistivity to conducting electricity below a certain critical temperature. The PI aims to investigate iron-based compounds where superconducting properties may coexist with magnetic properties with a delicate interplay between each other. The main emphasis of this project is on revealing how these systems conduct electricity and heat, how robust are their properties under external stimuli, and studying their fundamental limits of their potential practical applications. The research will have a broad impact on the scientific community, postsecondary science students, and public audiences. These audiences will be reached, respectively, through conferences and journal publications, formal university courses, and an extensive public science engagement program. A strong emphasis is placed on outreach activities involving the interscholastic science olympiad, and attracting students from socioeconomically disadvantaged and underrepresented groups to consider careers in science.TECHNICAL SUMMARY This award supports theoretical research and education on nonequilibrium and transport properties of several confined low-dimensional materials and materials systems where low dimensionality plays a role. The primary aim of this project is to develop a stochastic kinetic and hydrodynamic theory of meso and nanoscale strongly correlated systems. The technical analytical methods are based on Keldysh field theory built into the framework of the nonlinear sigma model and bosonization technique. These theoretical approaches will be applied to various systems. The goals of this project include: (1) Out of equilibrium nonlinear, spiral and helical Luttinger liquids. The PI aims to study quantum quench relaxation and thermalization in generic nonintegrable one-dimensional liquids, reveal emergent physics phenomena beyond the Luttinger liquid paradigm, investigate transport at the edges of quantum spin Hall insulators, and investigate proximity effect phenomena between superconductors and wires with spin-orbit interaction. (2)Kinetics of strongly correlated two-dimensional systems. This research direction covers new aspects of hydrodynamic Coulomb drag, spin-mediated mechanisms of magnetodrag as well as novel mechanisms of photoresistance of two-dimensional electron systems in a quantizing magnetic field. (3)Unconventional and topological nonequilibrium superconductivity. The PI plans to investigate fluctuations and quantum criticality in the iron-pnictide superconductors, search for novel collective modes in the coexistence phase and to describe dynamics initiated by optical excitation. The PI will also develop thermomagnetic transport theory of Pauli limited ultra-thin superconducting films and study transport phenomena occurring at the surface states of topological insulators and superconductors.A postdoctoral researcher and graduate students working on this project will receive extensive training by studying modern aspects of condensed matter physics, developing new conceptual approaches to nonequilibrium systems and conducting original research. The technical and theoretical methods that will be developed as a part of this project are relevant to a much wider class of problems in the quantum physics of many-body systems. The results of the proposed work will be widely disseminated in publications, seminars, colloquia and conference presentations. Educational aspects will be integrated through the development of courses directly related to the proposed research and through research-related seminars, coaching and supervising interscholastic science olympiads, and meetings that target high-school teachers.

非技术性摘要该奖项支持理论研究和教育关于新型物质的特性的理论研究和教育。 纳米级，材料科学和实验技术的材料和材料系统制造的最新进展使得以前所未有的准确性和控制水平来研究新型的电子系统和量子机械现象。当电子在空间上紧密限制时，它们的波形性质会导致受量子力学控制的干扰效应，并且颗粒之间的相互作用导致形成了新型电子强度态的新型电子状态。这些系统提供了新的概念科学挑战，可能对各种未来的电子技术应用有用。在与实验组密切合作的情况下，PI旨在研究运输特性，例如这些系统如何进行电力，重点是发现新的运输现象。与此研究相关的系统包括Luttinger液体，这些系统与具有纳米表直径的量子线和毫米尺度的量子尺度直径和几乎完美的单次量度环境相关的量子线相关。半导体结构中称为量子孔的电子可以被操纵以形成二维液体，如果相互作用足够强，则电子可能会结晶。其他相关系统包括最近发现的拓扑绝缘子，它们是散装中的绝缘体，但在样品表面或边缘几乎是理想的导体。超导体是该项目的重要重点。它们显示出对在一定临界温度以下传导电力的消失电阻率。 PI的目的是研究基于铁的化合物，在这些化合物中，超导性能可能与磁性特性并存，彼此之间存在微妙的相互作用。该项目的主要重点在于揭示这些系统如何进行电力和热量，外部刺激下的特性如何鲁棒，并研究其潜在实际应用的基本限制。 这项研究将对科学界，高等科学学生和公众受众产生广泛的影响。将分别通过会议和期刊出版物，正规大学课程和广泛的公共科学参与计划分别与这些受众联系。非常重视涉及校际科学奥林匹克的外展活动，并吸引来自社会经济处于弱势群体的学生，且代表性不足的群体来考虑科学的职业。技术总结该奖项支持理论研究和教育在几个较低的材料和低层次材料系统的非平衡和运输方面的非平衡和运输属性，而低层次的材料系统则是一项低层次的功能。该项目的主要目的是开发一种随机动力学和流体动力学理论，对中心和纳米级的系统强烈相关。技术分析方法基于基于非线性Sigma模型和琼脂化技术框架中的Keldysh现场理论。这些理论方法将应用于各种系统。该项目的目标包括：（1）从平衡的非线性，螺旋和螺旋luttinger液体中。 PI旨在研究通用不可构造的一维液体中的量子淬灭松弛和热化，揭示了超越Luttinger液体液体范式以外的新兴物理现象，研究量子自旋霍尔绝缘子边缘的运输，并研究超管体之间的近端效应现象和与Spin-Orbit相互作用的电线之间的接近效应现象。 （2）密切相关的二维系统的动力学。该研究方向涵盖了流体动力库仑阻力的新方面，磁磁体的自旋介导的机制以及在量化磁场中二维电子系统的光震动机制。 （3）非常规和拓扑非平衡超导性。 PI计划研究铁刺剂超导体中的波动和量子关键，在共存阶段寻找新型的集体模式，并描述通过光激发引发的动力学。 PI还将开发Pauli的热磁性运输理论有限的超薄超导膜和研究运输现象发生在拓扑绝缘体和超导体的表面状态。一名研究人员和从事该项目的研究生将通过研究凝聚力物质的现代概念方法，并进行新的概念材料的现代化，并进行新的概念材料，从而获得了广泛的培训，并进行了新的概念图。作为该项目的一部分将开发的技术和理论方法与多体系统的量子物理学中的一系列问题有关。拟议作品的结果将在出版物，研讨会，座谈会和会议演讲中广泛传播。教育方面将通过与拟议的研究直接相关的课程以及与研究相关的研讨会，教练和监督校际科学奥林匹克运动会以及针对高中教师的会议来整合。