Correlated Electron Transport in Mesoscopic Structures

该奖项支持介观物理领域的理论研究和教育。研究的重点是介观相互作用电子系统的低能性质，以及这些性质与这类系统的电子输运特性之间的关系。将研究电子在含有磁性杂质的量子线、量子和介观导体中的传输。该项目包括三个部分。第一部分研究磁性杂质对介观金属低温电导的影响。巡回电子与磁性杂质的相互作用会引起电子能量和相的驰豫，从而影响电导。弛豫速率可以由使杂质自旋极化的磁场控制。研究了部分自旋极化对电导的影响。该项目的第二部分探索了超越Luttinger液体模型的相互作用的一维电子系统的性质。为了准确地描述一些可观察到的现象，这种理论的扩展是必要的。这一部分还考虑了弱耦合量子线之间的库仑阻力以及磁场作用下电子对量子线的隧穿效应。阻力电阻率的计算需要考虑电子速度与动量的依赖关系；这种依赖关系在Luttinger液体模型中被忽略了。磁场引起电子光谱的塞曼分裂，从而导致微分隧道电导的有限偏置极大值。为了描述这种效应，我们还需要对Luttinger液体模型进行推广。该项目的第三部分探索了在量子点设备中观察到费米液体行为违规的可能性，这种违规行为是对称多通道近藤问题的特征。这里将考虑不可避免的对称性偏差所起的作用。还将特别强调通过研究通过这种装置的电子传输来寻找检测非费米液体行为的方法。这项研究将需要各种凝聚态理论技术，包括近藤效应的图解展开、重整化群理论和费米液体理论，使用精确可解的一维模型，以及玻色化技术。这项工作的广泛影响包括教育和对可能构成未来器件技术基础的知识基础的贡献。这项工作支持对学生和博士后研究助理进行现代凝聚态理论和纳米材料方法的教育。该项目涉及新系统和材料(纳米线、量子点、碳纳米管)的基础物理研究，这些都是未来电子技术的潜在元素。该奖项支持中观和纳米物理的理论研究和教育。研究的重点是低维系统中电子-电子相互作用对低能性质的影响以及这类系统的电子输运性质。我们将使用理论凝聚态物理中的先进方法来研究电子在量子线(一维)、量子点(零维)和含有磁性杂质的介观导体中的输运。这些材料和纳米结构中的低维和电子-电子相互作用的结合可以导致与宏观材料显著不同的新的电子态。这项工作的更广泛影响包括教育和对可能构成未来设备技术基础的知识基础的贡献。这项工作支持对学生和博士后研究助理进行现代凝聚态理论和纳米材料方法的教育。该项目研究新型系统和材料(纳米线、量子点、碳纳米管)的基础物理，这些都是未来电子技术的潜在元素。***

0237296GlazmanThis award supports theoretical research and education in the area of mesoscopic physics. Research focuses on the low-energy properties of mesoscopic interacting electron systems and on finding the relations between these properties and the electron transport characteristics of such systems. Electron transport in quantum wires, quantum, and mesoscopic conductors containing magnetic impurities will be studied. The project has three parts. The first part is devoted to the effect of magnetic impurities on the low-temperature conductance of mesoscopic metals. Interaction of itinerant electrons with the magnetic impurities causes relaxation of electron energy and phase, and thus affects the conductance. The rate of relaxation may be controlled by a magnetic field which polarizes impurity spins. The effect of partial spin polarization on the conductance will be studied. The second part of the project explores the properties of interacting one-dimensional electron systems beyond the Luttinger liquid model. This extension of theory is needed for the accurate description of a number of observable phenomena. This part also considers the Coulomb drag between two weakly-coupled quantum wires and electron tunneling into a quantum wire in the presence of a magnetic field. Calculation of the drag resistivity requires accounting for the dependence of electron velocity on momentum; this dependence is left out in the Luttinger liquid model. A magnetic field causes the Zeeman splitting of the electron spectrum, which results in finite-bias maxima in the differential tunneling conductance. To describe this effect, one also needs an extension of the Luttinger liquid model. The third part of the project explores the possibility of observing a violation of the Fermi-liquid behavior in a quantum dot device, a violation that is characteristic of a symmetric multi-channel Kondo problem. Here the role of inevitable deviations from the symmetry will be considered. Special emphasis will be placed also on finding ways to detect the non-Fermi-liquid behavior by studying the electron transport through such a device. This research will require a variety of condensed matter theory techniques, including diagrammatic expansions, renormalization group theory and Fermi liquid theory of the Kondo effect, the use of exactly solvable one-dimensional models, and the bosonization technique.Broader impacts of this work include education and the contribution to a base of knowledge that may form the foundation of future device technologies. This work supports the education of students and post-doctoral research associates in modern methods of condensed matter theory and nanoscale materials. The project involves the study of fundamental physics of novel systems and materials (nano-wires, quantum dots, carbon nanotubes) which are potential elements of future electronic technology. %%%This award supports theoretical research and education in mesocopic and nanoscale physics. Research focuses on the effect of electron-electron interactions on low-energy properties in low dimensional systems and on the electron transport properties of such systems. Electron transport in quantum wires (one-dimensional), quantum dots (zero-dimensional), and mesoscopic conductors containing magnetic impurities will be studied using advanced methods in theoretical condensed matter physics. The combination of low-dimensionality and electron-electron interactions in these materials and nanostructures can lead to novel electronic states that differ remarkably from those of macroscopic materials. Broader impacts of this work include education and the contribution to a base of knowledge that may form the foundation of future device technologies. This work supports the education of students and post-doctoral research associates in modern methods of condensed matter theory and in nanoscale materials. The project studies the fundamental physics of novel systems and materials (nano-wires, quantum dots, carbon nanotubes) which are potential elements of future electronic technology. ***