Scattering Theory and Non-Equilibrium Transport in Quantum

散射理论和量子非平衡输运

• 批准号: 1006684
• 负责人: Natan Andrei
• 金额: $ 28.5万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2014-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006684&HistoricalAwards=false
• 关键词: Scattering; Theory; Non; Equilibrium; Transport

TECHNICAL SUMMARYThis award supports theoretical research and education on dynamics of strongly correlated nanostructures out of equilibrium. The project will contribute to our understanding of how to describe interacting quantum systems carrying currents imposed by leads kept at different chemical potentials or temperatures, a subject of fundamental importance for theory and experiment with significant practical applications. The research combines several topical areas: the study of strongly correlated electron systems which seeks to understand new collective phenomena brought about by interactions; the study of nanostructures involving problems of transport and spectral properties analyzed in restricted geometries with emphasis on the interplay between disorder and interactions; nonequilibrium thermodynamics in many-body quantum systems. All these areas provide essential components in the study of the dynamics in nanoscale devices. Advances in fabrication have made nanodevices accessible to experiment. So, fundamental issues of nonequilibrium physics can be tested experimentally with a high degree of precision. This requires detailed theoretical predictions that the PI aims to provide. The theoretical approach to be pursued is based on scattering theory with the scattering eigenstates constructed via the Bethe Ansatz. The eigenstates are defined on the open infinite line with boundary conditions set by the bias voltage or temperature drop imposed by the leads. One obtains explicit predictions for non-equilibrium properties, such as charge and heat currents, entropy production and dissipation, as well as for quantities central in mesoscopics such as decoherence times and relaxation rates. All of these quantities can be experimentally tested.The PI will apply this approach to concrete models of nonequilibrium systems, including: the two leads Anderson model to model a quantum dot, the two leads Holstein model to model molecules in break junctions, and the two leads AB interferometer. The PI aims to develop precise predictions that can be compared with experiment and may lead to new insights about steady-state behaviors. This project contributes to the education of postdocs and student researchers in learning advanced theoretical techniques and their application to concrete experimental systems. The PI is also currently writing a book on nonperturbative approaches to quantum impurity systems.NONTECHNICAL SUMMARYThis award supports theoretical research and education on dynamics of electrons which interact strongly with each other in systems of atoms that are some ten to hundred times smaller than the diameter of a human hair. The PI will focus on situations where the electrons in these nanostructures are not in the balanced and tranquil state of equilibrium. Rather, the PI will investigate situations where the electrons are far from equilibrium as might happen when a voltage is applied across a nanostructure forcing the electrons to move. Systems far from equilibrium are not well understood. The correlated motion of electrons that results from their strong interaction provides additional complexity, but is an important ingredient to include in order to develop the theoretical and conceptual tools that enable the modeling and design of the necessarily quantum mechanical electronic devices that may be developed on the nanoscale. Postdocs and student researchers will be involved in the research, which will contribute to their education in advanced theoretical techniques and the application of these techniques to materials and systems at the blurry interface of materials and devices on the nanoscale.

技术摘要该奖项支持强相关纳米结构失平衡动力学的理论研究和教育。该项目将有助于我们理解如何描述由保持在不同化学势或温度的引线施加的电流相互作用的量子系统，这对于理论和实验具有重要的实际应用具有根本重要性。该研究结合了几个主题领域：强相关电子系统的研究，旨在了解相互作用带来的新集体现象；纳米结构的研究涉及在受限几何形状中分析的传输和光谱特性问题，重点是无序和相互作用之间的相互作用；多体量子系统中的非平衡热力学。所有这些领域都为纳米级器件动力学研究提供了重要组成部分。制造技术的进步使得纳米器件可以进行实验。因此，非平衡物理的基本问题可以通过实验高精度地进行测试。这需要 PI 旨在提供详细的理论预测。 所追求的理论方法基于散射理论，并通过 Bethe Ansatz 构建了散射本征态。本征态定义在开放无限线上，其边界条件由引线施加的偏置电压或温降设置。人们可以获得对非平衡特性的明确预测，例如电荷和热流、熵的产生和耗散，以及介观的中心量，例如退相干时间和弛豫率。 所有这些量都可以通过实验进行测试。PI 将将此方法应用于非平衡系统的具体模型，包括：用于模拟量子点的两引线安德森模型、用于模拟断裂结中的分子的两引线荷斯坦模型以及用于模拟断裂结中分子的两引线 AB 干涉仪。 PI 旨在开发可与实验进行比较的精确预测，并可能带来关于稳态行为的新见解。该项目有助于教育博士后和学生研究人员学习先进的理论技术及其在具体实验系统中的应用。 PI 目前还在撰写一本关于量子杂质系统的非微扰方法的书。非技术摘要该奖项支持电子动力学的理论研究和教育，这些电子在比人类头发直径小十到一百倍的原子系统中相互作用强烈。 PI 将重点关注这些纳米结构中的电子不处于平衡和平静状态的情况。相反，PI 将研究电子远离平衡的情况，就像在纳米结构上施加电压迫使电子移动时可能发生的情况一样。远离平衡的系统还没有被很好地理解。电子的强相互作用产生的相关运动提供了额外的复杂性，但它是开发理论和概念工具的重要组成部分，这些工具能够对可能在纳米尺度上开发的必要量子力学电子设备进行建模和设计。博士后和学生研究人员将参与这项研究，这将有助于他们接受先进理论技术的教育，并将这些技术应用于纳米尺度材料和设备模糊界面的材料和系统。