Nonequilibrium Quantum Mechanics of Strongly Correlated Systems

强相关系统的非平衡量子力学

基本信息

批准号：
1303177
负责人：
Aditi Mitra
金额：
$ 28.5万
依托单位：
New York University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-01 至 2017-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1303177&HistoricalAwards=false
关键词：
Nonequilibrium Quantum Mechanics Strongly Correlated

项目摘要

TECHNICAL SUMMARYThis award supports theoretical research and education to study of nonequilibrium phenomena in strongly correlated quantum systems. The research has three thrusts:1). Quench dynamics in closed quantum systems with applications to cold-atomic gases and toultra-fast pump-probe spectroscopy of solid-state systems. The PI will build on her recent work where a novel renormalization group approach to study the dynamics of strongly correlated systems near critical points was developed. The PI aims to generalize this approach to study: one-dimensional systems where both disorder and interactions are present, quantum quenches in higher spatial dimensions, and a new kind of dynamical phase transition where a closed quantum system in the thermodynamic limit shows non-analytic behavior during its time-evolution. 2). Light-matter coupled systems where the interaction between two-level systems and photons can effectively lead to strongly correlated states of photons. The PI will include both strong driving and dissipation, which appear in experimental realizations of these systems, in the study of these systems. The PI will explore how different kinds of dissipative environments which are non-Markovian in nature affect the physics of the correlated states.3). Transport in nanoscale systems. Nonperturbative methods such as 1/N expansion techniques will be used to study the underscreened Kondo model in which a spin much greater 1 is coupled to current carrying leads. This part of the project has relevance to transport through spin clusters.This award supports active participation of graduate and undergraduate student, and the PI's efforts in K-12 outreach activities that are part of a continuing partnership between the NYU physics department and local schools. NON-TECHNICAL SUMMARYThe award supports theoretical research and education to explore the properties of quantum mechanical systems, such as small assemblies of atoms, that are far from the steady balance of equilibrium. This nonequilbrium state often results when the quantum mechanical system has been subjected to strong forces that act for a short period of time causing the system to change rapidly with time. Important questions arise as to how the system changes in time and how long the system takes to eventually establish a balance with its surroundings. Another way for a quantum system to go out of balance is by subjecting it to a continuous application of an external force. Large and complex systems, despite the steady application of a force, can reach a steady state that is independent of time. This time-independent state can have unusual properties not encountered in systems that are in balance with their surroundings. The PI plans to explore quantum systems in these two kinds of out of balance situations. Out-of-balance systems are challenging topics to study; the PI will develop new theoretical techniques to advance understanding of these ubiquitous systems. Understanding out of balance systems at a fundamental level is important for technological advancement such as for the development of future devices that will be nanometer sized, like a molecule, and will be manipulated by the flow of electric current and by light. On this scale the distinction between material and device becomes blurred.The proposal has a strong educational component as it will involve active participation of graduate and undergraduate students. The results of the projects will be presented at schools, workshops and conferences by the students as well as the PI. In addition, the PI will participate in outreach activities that are part of a continuing partnership between the NYU physics department and local schools.

技术摘要这一奖项支持理论研究和教育，以研究密切相关的量子系统中的非平衡现象。这项研究有三个推力：1）。在固定气体中应用的封闭量子系统中的动力学在固态系统的冷原子气体和toultra-fast-fast泵送光谱方面进行了淬灭。 PI将基于她最近的工作，其中开发了一种新型的重新归一化组方法来研究关键点附近强相关系统的动态。 PI旨在概括这种研究方法：存在障碍和相互作用的一维系统，较高空间维度的量子淬灭以及一种新型的动力学相变，其中热力学极限中的封闭量子系统在其时间进化过程中表现出非分析行为。 2）。轻度耦合系统，其中两级系统与光子之间的相互作用可以有效地导致光子的密切相关状态。 PI将包括强大的驾驶和耗散，这些驾驶和耗散出现在这些系统的实验实现中。 PI将探索本质上非马克维亚的不同种类的耗散环境如何影响相关状态的物理。3）。纳米级系统的运输。非扰动方法（例如1/n扩展技术）将用于研究强调的围绕模型，在该模型中，其中旋转与当前的携带导线耦合。该项目的这一部分与通过旋转群集运输相关。该奖项支持研究生和本科生的积极参与，以及PI在K-12外展活动中的努力，这些活动是纽约大学物理学系与当地学校之间持续合作的一部分。非技术摘要该奖项支持理论研究和教育，以探索量子机械系统的特性，例如原子的小组件，这些系统远非平衡的稳定平衡。当量子机械系统受到很短的时间作用，导致系统随着时间的变化而迅速变化时，这种非排序状态通常会产生。关于系统如何在时间上变化以及系统最终与周围环境建立平衡所需的时间。量子系统失去平衡的另一种方法是使其持续使用外力。大型且复杂的系统尽管稳定地应用了力，但仍可以达到独立于时间的稳态。这种独立的状态可能具有与周围环境平衡的系统中不会遇到的异常属性。 PI计划在这两种不平衡情况下探索量子系统。平衡系统是挑战性研究的主题。 PI将开发新的理论技术，以提高对这些普遍存在系统的理解。了解基本水平的平衡系统对于技术进步非常重要，例如，将未来设备的开发（如分子）大小，并且会被电流的流动和光所操纵。在此规模上，材料和设备之间的区别变得模糊。该提案具有强大的教育成分，因为它将涉及研究生和本科生的积极参与。这些项目的结果将在学生和PI的学校，研讨会和会议上呈现。此外，PI将参加纽约大学物理学系与当地学校之间持续合作的外展活动。