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.

该奖项支持关于强相关纳米结构动态平衡的理论研究和教育。该项目将有助于我们理解如何描述相互作用的量子系统，该系统承载由保持在不同化学势或温度下的引线施加的电流，这是一个具有重要实际应用的理论和实验的基本重要性的主题。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的集体现象;纳米结构的研究，涉及在限制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器件的动力学研究提供了必要的组成部分。制造技术的进步使得纳米器件可以进行实验。因此，非平衡物理学的基本问题可以通过实验进行高精度的检验。这需要PI旨在提供的详细理论预测。 要追求的理论方法是基于散射理论与散射本征态通过Bethe Anonymous构建。本征态定义在开路无限长线上，边界条件由引线施加的偏置电压或温度降设定。一个得到明确的预测非平衡性质，如电荷和热流，熵产生和耗散，以及在介观中心的数量，如退相干时间和弛豫速率。 PI将把这种方法应用于非平衡系统的具体模型，包括：模拟量子点的双引线安德森模型，模拟断裂结中分子的双引线Holstein模型，以及双引线AB干涉仪。PI旨在开发可以与实验进行比较的精确预测，并可能导致对稳态行为的新见解。该项目有助于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目前也在写一本关于量子杂质系统的非微扰方法的书。非技术性总结该奖项支持在原子系统中相互作用强烈的电子动力学的理论研究和教育，这些原子系统比人类头发的直径小10到100倍。PI将专注于这些纳米结构中的电子不处于平衡和平静的平衡状态的情况。相反，PI将研究电子远离平衡的情况，当在纳米结构上施加电压迫使电子移动时可能会发生这种情况。远离平衡的系统还没有被很好地理解。由它们的强相互作用产生的电子的相关运动提供了额外的复杂性，但是为了开发理论和概念工具，使能够建模和设计可能在纳米尺度上开发的必要的量子力学电子器件，这是一个重要的成分。博士后和学生研究人员将参与这项研究，这将有助于他们在先进的理论技术和这些技术的应用，以材料和系统的材料和纳米级设备的模糊界面的教育。