Dynamics of quantum many-body systems

量子多体系统动力学

• 批准号: 1613029
• 负责人: Victor Galitski
• 金额: $ 30万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1613029&HistoricalAwards=false
• 关键词: Dynamics; quantum; many; body; systems

NONTECHNICAL SUMMARYThis award supports fundamental theoretical condensed matter research and education aiming to extend our understanding of nonequilibrium quantum matter. A typical material or electronic device contains an immense number of electrons, which constitute a quantum many-body system - the subject of condensed matter research. The corresponding configuration space, the set of possible states the system can find itself in, is unimaginably large. In thermodynamic equilibrium, the situation is somewhat simplified in that the system occupies states that are close to the lowest-energy state in a rigorously prescribed manner, exploring only a tiny corner of the entire configuration space. This leads to a material with well-defined properties that are dictated by nature and are "non-negotiable."In contrast, a nonequilibrium system can explore the totality of the huge configuration space and may potentially find itself in a state with drastically modified electronic properties compared to those at equilibrium. Therefore, the ability to control dynamical properties of driven electronic states could open opportunities to design nonequilibrium electronic materials with desired properties, instead of relying on serendipity in equilibrium material physics. This project is focused on exploring fundamental aspects of the underlying physics that would make such nonequilibrium quantum control of electronic materials possible. Of particular interest in this project are many-body quantum systems under the influence of perturbations that are periodic in time, which in practice is often achieved by irradiating electronic materials by light. The project achieves broader impacts by bringing together ideas from different fields of physics and mathematics, integrating them into teaching, and communicating them to a wide audience, building on the PI's prior efforts. Mentoring of students will continue and will include a continuing collaboration with the Science Magnet Program at Montgomery Blair High School in Silver Spring, MD, and the historically black Howard University in Washington, DC. The outreach component will also include further development and refinement of PI's massive open online course "Exploring Quantum Physics."TECHNICAL SUMMARYThis award supports fundamental theoretical condensed matter research and education aiming to extend our understanding of nonequilibrium quantum matter. The emphasis is on relating exciting theoretical results and ideas to experiment, and communicating them to a broad audience. The research effort is focused on studies of dynamics of quantum many-body systems. Below is a list of three key research foci: 1. A periodically-driven rotor is a prototypical model that exhibits a transition to chaos in the classical regime and dynamical localization in the quantum regime. The Principal Investigator will explore interacting many-body generalizations of such nonlinear, periodically driven systems, which are expected to exhibit transitions from many-body quantum chaos to dynamical localization.2. Recent experiments have observed interesting light-induced states in topological materials, such as Floquet reconstruction of electronic bands by light and a photovoltage and gigantic surface life-time in topological insulators. Motivated by this experimental progress, this project aims to develop a theory of Floquet systems coupled to a heat bath. An ambitious goal here is to identify general principles of Floquet thermodynamics.3. Solitons are fascinating nonlinear phenomena that occur in a diverse array of classical and quantum systems. Relying on a series of exact results, obtained recently by the PI, it is proposed to consider dissipative dynamics of quantum solitons in superfluids. The study of nonequilibrium many-body systems would provide new insights into several classes of physically interesting and technologically important materials and has the potential to deliver results of fundamental and practical importance. For example, an understanding of the long-lived photoexcited states in topological insulators may provide a roadmap for creating novel devices, such as an optical p-n junction and a solar cell, based on light-induced topological surface states. The project achieves broader impacts by bringing together ideas from different fields of physics and mathematics, integrating them into teaching, and communicating them to a wide audience, building on the PI's prior efforts. Mentoring of students will continue and will include a continuing collaboration with the Science Magnet Program at Montgomery Blair High School in Silver Spring, MD, and the historically black Howard University in Washington, DC. The outreach component will also include further development and refinement of PI's massive open online course "Exploring Quantum Physics."

非技术摘要这一奖项支持基本理论凝结的物质研究和教育，旨在扩展我们对非平衡量子问题的理解。典型的材料或电子设备包含大量的电子，构成了量子多体系统 - 凝结物质研究的主题。系统可以找到自己的可能状态的相应配置空间是难以想象的。在热力学平衡中，情况有些简化，因为该系统占据了以严格规定的方式接近最低能量状态的状态，仅探索整个配置空间的一个小角落。这导致具有定义明确的特性的材料，该材料是由本质决定的，并且是“不可商服的”。相比之下，与平衡相比，非元素系统可以探索巨大的配置空间的总体，并有可能在具有巨大修改的电子特性状态下发现自己。因此，控制驱动电子状态的动态特性的能力可以打开设计具有所需特性的非平衡电子材料的机会，而不是依靠平衡材料物理学中的偶然性。该项目的重点是探索潜在物理学的基本方面，这些方面将使电子材料成为可能的非平衡量子控制。在这个项目中特别感兴趣的是在及时周期性的扰动影响下多体量子系统，实际上通常是通过光照射电子材料来实现的。该项目通过将物理和数学领域的想法汇总在一起，将它们整合到教学中，并将其传达给广泛的受众，从而实现更广泛的影响。学生的指导将继续，并将包括与马里兰州银泉市蒙哥马利布莱尔高中的科学磁铁计划以及华盛顿特区历史悠久的黑人霍华德大学的持续合作。外展部分还将包括对PI大规模开放在线课程“探索量子物理学”的进一步开发和完善。技术摘要这一奖项支持基本的理论凝结问题研究和教育，旨在扩展我们对非平衡量子问题的理解。重点是将令人兴奋的理论结果和思想联系起来，并将它们传达给广泛的受众。研究工作的重点是量子多体系统动力学的研究。以下是三个关键研究焦点的列表：1。定期驱动的转子是一个典型的模型，在经典制度中表现出过渡到混乱的过渡和量子状态中的动态定位。主要研究者将探索这种非线性，定期驱动的系统的相互作用的多体概括，这些系统有望展示从多体量子混乱到动态定位的过渡。2。最近的实验观察到了拓扑材料中有趣的光引起的状态，例如通过光对电子带的浮部重建以及拓扑绝缘子中的光电波和巨大的表面寿命。在这个实验进步的动机中，该项目旨在开发一种浮子系统的理论，结合了热水浴。这里的一个雄心勃勃的目标是确定浮雕热力学的一般原则3。在各种古典和量子系统中，孤子群是令人着迷的非线性现象。依靠PI最近获得的一系列精确结果，建议考虑超氟中量子孤子的耗散动力学。对多体系统的非平衡性研究将为几类具有物理有趣且技术上重要的材料提供新的见解，并有可能提供基本和实际重要性的结果。例如，对拓扑绝缘体中长期光激发状态的理解可能为创建新型设备（例如光学P-N连接和太阳能电池）提供了路线图，基于光诱导的拓扑表面状态。该项目通过将物理和数学领域的想法汇总在一起，将它们整合到教学中，并将其传达给广泛的受众，从而实现更广泛的影响。学生的指导将继续，并将包括与马里兰州银泉市蒙哥马利布莱尔高中的科学磁铁计划以及华盛顿特区历史悠久的黑人霍华德大学的持续合作。外展部分还将包括对PI大规模开放在线课程“探索量子物理学”的进一步开发和完善。