CAREER: Non-equilibrium quantum dynamics, topology, and criticality

非技术性总结该职业奖支持理论研究和教育，以理解和控制复杂量子系统的动力学。量子力学的特殊性质使全新的计算、加密和通信方法成为可能，其速度远远超过经典方法。利用这些特性的技术需要能够控制和操纵复杂的物理系统，同时保持其微妙的量子结构。到目前为止，量子技术只在非常小的系统中成功实现，其中每个细节都可以完全表征和控制，这对大规模实施构成了障碍。相比之下，宏观量子材料表现出显着的普遍现象，例如超导性和磁性，对潜在的细节不敏感。然而，这些复杂的量子系统通常有太多的运动部件，无法精确控制，通常会导致编码信息在使用之前迅速混乱。该项目旨在通过确定鲁棒的、抗错误的方法来控制宏观系统中的量子运动，而无需单独控制每个单独的部件，从而弥合这两种机制之间的差距。这将通过探索孤立量子系统中物质的新领域来实现，这些量子系统与外界隔绝，但使用例如调制光的照射远离传统的平衡设置。该研究将建立新的理论和计算工具来模拟复杂量子系统的动力学，并开发通用的组织原理来理解它们的特性。研究生和本科生将在研究工作中发挥不可或缺的作用，同时建立自己的学位。与此同时，PI将为学生创建新的并加强现有的K-12外展计划，为妇女，残疾人和代表性不足的少数群体创造机会，以了解和参与科学研究。PI还将开发一个新的跨学科大学课程，在日益共生但传统上分离的理论物理子领域之间建立跨学科的联系。技术总结该职业奖支持理论研究和教育，以识别，理解和控制复杂量子多体系统中的相干非平衡动力学的普遍制度。普适性在复杂的多体系统中通常是难以捉摸的，因为它们的混沌内部动力学迅速导致热平衡，产生不相干的经典动力学。该项目旨在寻找违背热平衡“定律”的内在量子相干动力学稳态，包括三个方面：1）将系统与环境隔离，并添加强无序可以无限期地阻止热化并导致多体局域化现象。PI将通过开发新的数值重整化群技术和基于张量网络方法的分析方法来描述这一类新的临界现象，研究平衡热力学如何在局部化开始时急剧崩溃。2）以时间相关的方式驱动量子系统可以实现非平衡稳态。3）PI将研究如何利用非热态和量子动力学来构建纠缠光源，在耗散系统中获得新的非平衡相，以及设计新的方法来动态探测平衡量子材料的性质。这些方向的灵感来自原子，分子和光学系统，可以很好地与它们的环境隔离，并且可以以很高的精度和灵活性进行动态操纵。这项研究可以在这些系统中实现新的动力学宏观量子现象，而不需要严格的冷却，为它们的实验探索提供了强大的优势。这些想法的应用到固态系统和新的计算方法也将被开发。研究生和本科生将在研究工作中发挥不可或缺的作用，同时建立自己的学位。与此同时，PI将为学生创建新的并加强现有的K-12外展计划，为妇女，残疾人和代表性不足的少数群体创造机会，以了解和参与科学研究。PI还将开发一个新的跨学科大学课程，以在日益共生但传统上分离的理论物理子领域之间建立跨学科联系。

NONTECHNICAL SUMMARYThis CAREER award supports theoretical research and education towards understanding and controlling the dynamics of complex quantum systems. The peculiar properties of quantum mechanics enable fundamentally new computing, cryptographic, and communication methods that far outpace their classical counterparts. Harnessing these properties for technology requires the ability to control and manipulate complex physical systems while preserving their delicate quantum structure. To date, quantum technologies have only been successfully implemented in very small systems for which every detail can be completely characterized and controlled, presenting a barrier to large scale implementation. In contrast, macroscopic quantum materials exhibit remarkable universal phenomena, e.g. superconductivity and magnetism, that are insensitive to the underlying minutiae. However, these complex quantum systems often have too many moving parts to precisely control, typically leading to rapid scrambling of encoded information before it can be utilized.This project aims to bridge the gap between these two regimes by identifying robust, error-resistant ways to control quantum motion in macroscopic systems, without separately controlling each individual piece. This will be done by exploring new realms of matter in isolated quantum systems that are cut off from the outside world, but are driven far from conventional equilibrium settings using, for example, irradiation by modulated light. The research will build new theoretical and computational tools for simulating the dynamics of complex quantum systems, and develop universal organizing principles to understand their properties. Graduate and undergraduate students will play an integral role in the research efforts, while building towards their degrees. In conjunction, the PI will create new and enhance existing K-12 outreach programs for students, building opportunities for women, persons with disabilities, and for underrepresented minority groups to learn about and participate in scientific research. The PI will also develop a new interdisciplinary university curriculum to build interdisciplinary connections among increasingly symbiotic but traditionally separated subfields of theoretical physics.TECHNICAL SUMMARYThis CAREER award supports theoretical research and education to identify, understand, and control universal regimes of coherent nonequilibrium dynamics in complex quantum many-body systems. Universality is typically elusive in complicated many-body systems, as their chaotic internal dynamics rapidly lead towards thermal equilibrium producing incoherent classical dynamics. This project seeks to find intrinsically quantum coherent dynamical steady states that defy the "laws" of thermal equilibrium, and consists of three thrusts:1) Isolating a system from its environment, and adding strong disorder can indefinitely prevent thermalization and lead to the phenomena of many-body localization. The PI will investigate how equilibrium thermodynamics breaks down sharply at the onset of localization by developing new numerical renormalization group techniques and analytic methods based on tensor-network methods to describe this new class of critical phenomena.2) Driving a quantum system in a time-dependent fashion can achieve nonequilibrium steady states. The PI will explore how new dynamical topological phases with no equilibrium analog can be engineered by driving.3) The PI will investigate how non-thermal states and quantum dynamics can be used to build entangled light sources, to access new nonequilibrium phases in dissipative systems, and to devise new ways to dynamically probe the properties of equilibrium quantum materials.These directions are inspired by rapid experimental progress in atomic, molecular, and optical systems that can be well isolated from their environment and can be dynamically manipulated with great precision and flexibility. The proposed research can enable novel dynamical macroscopic quantum phenomena in these systems without the need for stringent cooling, offering strong advantages for their experimental exploration. Applications of these ideas to solid-state systems and new computational methods will also be developed.Graduate and undergraduate students will play an integral role in the research efforts, while building towards their degrees. In conjunction, the PI will create new and enhance existing K-12 outreach programs for students, building opportunities for women, persons with disabilities, and for underrepresented minority groups to learn about and participate in scientific research. The PI will also develop a new interdisciplinary university curriculum to build interdisciplinary connections among increasingly symbiotic but traditionally separated subfields of theoretical physics.