CAREER: Quantum many-body physics beyond the Boltzmann paradigm: prethermalization, many-body localization, and their applications

职业：超越玻尔兹曼范式的量子多体物理：预热、多体局域化及其应用

• 批准号: 2236517
• 负责人: Sarang Gopalakrishnan
• 金额: $ 48.43万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2236517&HistoricalAwards=false
• 关键词: CAREER; Quantum; many; body; physics

NONTECHNICAL SUMMARYThe Division of Materials Research and the Division of Physics contribute funds to this CAREER award, which supports theoretical research and education on the dynamics of quantum systems made up from many interacting particles. The project explores quantum systems that take anomalously long to approach thermal equilibrium (or, in some extreme cases, never approach equilibrium). The approach to equilibrium involves a system "forgetting" information about its initial state. For example, if a gas is initially put in the left side of a tube, and then is allowed to spread throughout the tube, it eventually forgets which side it started out in. This apparent "forgetting" is at odds with the laws of quantum mechanics, which in fact conserve information; it is believed that information about the initial state is never truly forgotten, but is stored in complicated, experimentally inaccessible correlations. How information migrates from measurable to hidden correlations is in general not understood. This project approaches the general question from the perspective of states of matter related to glasses, in which "forgetting" is extremely slow. In the intermediate regimes, some sectors of the system are in equilibrium, whereas others are far from it. New theoretical methods that generalize conventional statistical mechanics are required to characterize these intermediate regimes. Developing such methods and using them to identify distinctive features of these intermediate regimes are primary objectives of this project. The other major focus of this project is to use slowly equilibrating systems for novel quantum applications, including heat engines, quantum memories, and sensors. Since equilibration corresponds to the forgetting or hiding of information, systems that are slow to equilibrate retain information for very long times; this observation underlies the various applications that will be explored in this project. This project will take place at the College of Staten Island, which has a diverse student body including large proportions of first-generation college students, underrepresented minorities, and recent immigrants. Educational activities will include curricular development to make physics relevant for this wide range of students, including the reorientation of standard courses to emphasize general-purpose computational methods, which are useful in a wide range of professions, as well as development of new courses on complex systems. Outreach to the broader community will involve developing a mini museum that will illustrate universal phenomena in everyday life through simple interactive exhibits. TECHNICAL SUMMARYThe Division of Materials Research and the Division of Physics contribute funds to this CAREER award, which supports theoretical research and education on the properties of interacting quantum systems that approach thermal equilibrium anomalously slowly: i.e., systems for which the thermalization timescale is much longer than other intrinsic timescales. These include isolated systems that are nearly integrable or nearly many-body localized, as well as related open systems. The main goals of this project are threefold: to develop computational methods suited to slowly thermalizing systems, to characterize distinctively non-thermal features of distribution functions in such systems, and to apply these distinctive features to quantum technologies. The first main goal is to develop methods to describe the dynamics of slowly thermalizing systems. Existing approaches are typically limited to short times and/or small systems, owing to the growth of entanglement. This project will develop methods tailored to the intermediate and late-time behavior of slowly thermalizing systems. Specifically, field theories of the prethermalized regime, as well as mean-field and renormalization-group techniques that leverage the separation of timescales between interactions and thermalization to describe the emergence of thermal behavior. These methods will be applied to experiments involving ultracold atomic systems that are nearly integrable (one-dimensional dipolar gases) or many-body localized. The second main goal is to characterize the probability distributions of physical observables in slowly thermalizing systems, focusing on many-body localization. Such distributions are expected to be fat-tailed; this project will characterize these tails, and their implications for observables such as the nonlinear response. The third main goal is to explore applications of non-thermalizing systems (again, focusing on the many-body localized case) for quantum information science, quantum metrology, and quantum thermodynamics. This project will take place at the College of Staten Island, which has a diverse student body including large proportions of first-generation college students, underrepresented minorities, and recent immigrants. Educational activities will include curricular development to make physics relevant for this wide range of students, including the reorientation of standard courses to emphasize general-purpose computational methods, which are useful in a wide range of professions, as well as development of new courses on complex systems. Outreach to the broader community will involve developing a mini museum that will illustrate universal phenomena in everyday life through simple interactive exhibits.

非技术摘要材料研究部和物理部为该职业奖提供资金，该奖项支持由许多相互作用的粒子组成的量子系统动力学的理论研究和教育。该项目探索需要异常长时间才能达到热平衡（或者在某些极端情况下永远不会达到平衡）的量子系统。达到平衡的方法涉及系统“忘记”有关其初始状态的信息。例如，如果气体最初被放入管子的左侧，然后允许其扩散到整个管子，它最终会忘记它是从哪一侧开始的。这种明显的“忘记”与量子定律相矛盾机制，实际上保存信息；人们相信，有关初始状态的信息永远不会被真正忘记，而是存储在复杂的、实验上无法访问的关联中。一般来说，信息如何从可测量的相关性迁移到隐藏的相关性尚不为人所知。该项目从与眼镜相关的物质状态的角度来解决这个普遍问题，其中“遗忘”是极其缓慢的。在中间制度中，系统的某些部分处于平衡状态，而其他部分则远离平衡。需要概括传统统计力学的新理论方法来表征这些中间状态。开发此类方法并利用它们来识别这些中间制度的显着特征是该项目的主要目标。该项目的另一个主要重点是使用缓慢平衡系统来实现新颖的量子应用，包括热机、量子存储器和传感器。由于平衡对应于信息的遗忘或隐藏，因此平衡缓慢的系统会长时间保留信息；这一观察结果是本项目将探索的各种应用的基础。该项目将在史泰登岛学院进行，该学院拥有多元化的学生群体，其中包括大量第一代大学生、代表性不足的少数族裔和新移民。教育活动将包括课程开发，使物理学与广大学生相关，包括重新定位标准课程以强调通用计算方法，这些方法可用于广泛的专业，以及开发复杂的新课程系统。向更广泛的社区推广将涉及建立一个迷你博物馆，通过简单的互动展览展示日常生活中的普遍现象。 技术摘要材料研究部和物理部为这一职业奖提供资金，该奖项支持对异常缓慢地接近热平衡的相互作用量子系统的特性进行理论研究和教育：即热化时间尺度远长于热平衡的系统。其他内在的时间尺度。其中包括几乎可积或几乎多体局部化的孤立系统，以及相关的开放系统。该项目的主要目标有三个：开发适合缓慢热化系统的计算方法，表征此类系统中分布函数的独特非热特征，并将这些独特特征应用于量子技术。第一个主要目标是开发描述缓慢热化系统动力学的方法。由于纠缠的增长，现有方法通常仅限于短时间和/或小系统。该项目将开发适合缓慢热化系统的中期和后期行为的方法。具体来说，预热化状态的场论，以及利用相互作用和热化之间的时间尺度分离来描述热行为的出现的平均场和重正化群技术。这些方法将应用于涉及近可积（一维偶极气体）或多体定域的超冷原子系统的实验。第二个主要目标是表征缓慢热化系统中物理可观测值的概率分布，重点关注多体定位。这种分布预计是厚尾的；该项目将描述这些尾部的特征，以及它们对非线性响应等可观测值的影响。第三个主要目标是探索非热化系统（再次关注多体局域情况）在量子信息科学、量子计量学和量子热力学中的应用。该项目将在史泰登岛学院进行，该学院拥有多元化的学生群体，其中包括大量第一代大学生、代表性不足的少数族裔和新移民。教育活动将包括课程开发，使物理学与广大学生相关，包括重新定位标准课程以强调通用计算方法，这些方法在广泛的专业中有用，以及开发复杂的新课程系统。向更广泛的社区推广将涉及开发一个迷你博物馆，通过简单的互动展览展示日常生活中的普遍现象。

项目成果

Entanglement and absorbing-state transitions in interactive quantum dynamics

交互式量子动力学中的纠缠和吸收态跃迁

• DOI: 10.1103/physrevb.109.l020304
• 发表时间: 2024-01
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: O'Dea, Nicholas;Morningstar, Alan;Gopalakrishnan, Sarang;Khemani, Vedika
• 通讯作者: Khemani, Vedika

Divergent Nonlinear Response from Quasiparticle Interactions

准粒子相互作用的发散非线性响应

• DOI: 10.1103/physrevlett.131.256505
• 发表时间: 2023-12
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Fava, Michele;Gopalakrishnan, Sarang;Vasseur, Romain;Essler, Fabian;Parameswaran, S. A.
• 通讯作者: Parameswaran, S. A.

Full Counting Statistics of Charge in Chaotic Many-Body Quantum Systems

混沌多体量子系统中电荷的全面计数统计

• DOI: 10.1103/physrevlett.131.210402
• 发表时间: 2023-11
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: McCulloch, Ewan;De Nardis, Jacopo;Gopalakrishnan, Sarang;Vasseur, Romain
• 通讯作者: Vasseur, Romain

Critical phase and spin sharpening in SU(2)-symmetric monitored quantum circuits

SU(2) 对称监控量子电路中的临界相位和自旋锐化

• DOI: 10.1103/physrevb.108.054307
• 发表时间: 2023-08
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Majidy, Shayan;Agrawal, Utkarsh;Gopalakrishnan, Sarang;Potter, Andrew C.;Vasseur, Romain;Halpern, Nicole Yunger
• 通讯作者: Halpern, Nicole Yunger

Entanglement and Charge-Sharpening Transitions in U(1) Symmetric Monitored Quantum Circuits

U(1) 对称监测量子电路中的纠缠和电荷锐化跃迁

• DOI: 10.1103/physrevx.12.041002
• 发表时间: 2022-10
• 期刊: Physical Review X
• 影响因子: 12.5
• 作者: Agrawal, Utkarsh;Zabalo, Aidan;Chen, Kun;Wilson, Justin H.;Potter, Andrew C.;Pixley, J. H.;Gopalakrishnan, Sarang;Vasseur, Romain
• 通讯作者: Vasseur, Romain