Strongly Correlated Nonequilibrium Transport Simulation in Complex Quantum Dot and Bulk Systems

复杂量子点和体系统中的强相关非平衡输运模拟

• 批准号: 0907150
• 负责人: Jong Han
• 金额: $ 28.42万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0907150&HistoricalAwards=false
• 关键词: Strongly; Correlated; Nonequilibrium; Transport; Simulation

TECHNICAL SUMMARYThis award supports computational and theoretical research and education on quantum nonequilibrium effects in mesoscopic and nanosystems. Based on the PI?s recent imaginary-time formulation of steady-state nonequilibrium transport, complex quantum dot systems will be studied via quantum Monte Carlo technique and other numerical many-body tools through the Matsubara voltage method. The PI will apply this formalism to nonlinear transport problems of complex quantum models which are currently difficult to study through computation. Recent experiments on several molecular junctions show a Kondo zero-bias anomaly accompanied by conductance oscillations at the source-drain bias comparable to the Kondo energy scale. The oscillation has been speculated to be from molecular vibrations. The PI will pursue an Anderson-Holstein model to investigate the roles of non-Jahn-Teller and Jahn-Teller electron-phonon coupling, and the on-site Coulomb interaction. The PI will study strong correlation effects in spin-injection proposed for spintronics devices. The nonequilibrium theory will be extended to the bulk limit using two different implementations of the dynamical mean-field theory: effect of multiple-chemical potentials in Fermi lattice and electric field driven transport of charged particles using the Bloch oscillation basis.The PI is actively involved in interdisciplinary research with the Electric Engineering and Mechanical Engineering Departments, and also in outreach effort of artistic representation of physics ideas in collaboration with the department of visual studies.NONTECHNICAL SUMMARYThis award supports theoretical research and education to study mesoscopic systems and nanostructures, such as large molecules or interconnected systems of large molecules, that are out of balance with their surroundings due to, for example, the application of an electric field, and for which quantum mechanics dominates. This research builds on methods developed by the PI that will enable him to calculate how well these structures conduct electricity and to explore new phenomena. Motivated by experiments, the PI will apply his approach to determine how strong interactions among electrons, and electrons and phonons affect the transport of electrons through the structures. This research contributes to the broad fundamental understanding of the phenomena that arise in the world around us. Conventional theories used to develop semiconductor devices become increasingly inadequate to describe devices now approaching the size molecules where the notion of a device and material become increasingly blurred. This effort contributes to the intellectual foundations for future technologies that would utilize molecules and nanoscale structures to construct electronic devices as a strategy to sustain the tremendous growth of the electronics industry encapsulated in ?Moore?s Law.? This research project contributes to the general understanding of quantum mechanical nonequilibrium behavior of mesoscale and nanoscale structures coupled to open systems. The general problem of how quantum information is transported and lost through coupling to the environment has impact on the emerging area of quantum computing.The PI is actively involved in interdisciplinary research with the Electric Engineering and Mechanical Engineering Departments, and also in outreach effort of artistic representation of physics ideas in collaboration with the department of visual studies.

该奖项支持介观和纳米系统中量子非平衡效应的计算和理论研究和教育。根据PI？在Matsubara电压方法的基础上，利用量子MonteCarlo技术和其他数值多体方法，研究了复杂量子点系统的稳态非平衡输运。PI将把这种形式应用于目前难以通过计算研究的复杂量子模型的非线性输运问题。最近几个分子结的实验表明，近藤零偏置异常伴随着电导振荡的源漏偏置可比近藤能量尺度。这种振荡被推测是由分子振动引起的。PI将采用Anderson-Holstein模型来研究非Jahn-Teller和Jahn-Teller电子-声子耦合以及现场库仑相互作用的作用。PI将研究为自旋电子器件提出的自旋注入中的强关联效应。使用两种不同的动力学平均场理论，非平衡理论将被扩展到体积极限：费米晶格中的多重化学势效应和使用布洛赫振荡基础的电场驱动带电粒子输运。PI积极参与电气工程和机械工程系的跨学科研究，该奖项支持理论研究和教育，以研究介观系统和纳米结构，如大分子或大分子的互连系统，由于例如电场的应用而与其周围环境不平衡，并且量子力学占主导地位。这项研究建立在PI开发的方法基础上，使他能够计算这些结构的导电能力并探索新现象。受实验的启发，PI将应用他的方法来确定电子之间的相互作用以及电子和声子之间的相互作用如何影响电子通过结构的传输。这项研究有助于对我们周围世界中出现的现象进行广泛的基本理解。用于开发半导体器件的传统理论越来越不足以描述现在接近分子大小的器件，其中器件和材料的概念变得越来越模糊。这一努力有助于未来技术的知识基础，将利用分子和纳米结构来构建电子设备，作为一种战略，以维持封装在？摩尔？s法。？本研究计画有助于了解介观尺度与奈米尺度结构耦合于开放系统之量子力学非平衡行为。量子信息如何通过耦合到环境中传输和丢失的一般问题对量子计算的新兴领域产生了影响。PI积极参与电子工程和机械工程系的跨学科研究，并与视觉研究部门合作，积极参与物理思想的艺术表现的推广工作。