CAREER: Quantum mechanics far from equilibrium: Matter-wave turbulence

在过去的几十年里，对量子物质平衡相的理解有了很大的进展。统计力学和线性响应理论的工具非常适合于理解这些相的平衡和近平衡性质。这种普遍的方法在过去世纪凝聚态物理学中产生了最重要的范式和技术突破。另一方面，远离平衡态的量子多体物理学是现代物理学的前沿，对物质的新范式和新动力学相的探索是开放和非常活跃的。湍流态--以时空混沌为特征的远离平衡态的动态场--可以说是非平衡多体态家族中最不为人所知的。该项目的核心科学目标是发展新生的物质波湍流领域，作为理解这种状态和一般远离平衡的量子动力学问题的框架。在可编程光学势中捕获和控制的超冷原子的物质波为这项工作提供了一个近乎理想的平台。由于量子技术在当今社会中发挥着越来越重要的作用，该项目的教育部分旨在通过系列讲座，实践研讨会和更先进的实验，让更广泛的受众了解量子物理学。经典场和量子场的远离平衡态动力学几乎不可避免地导致湍流现象。然而，迄今为止，湍流和量子动力学主要是由不同的科学团体研究的。鉴于流体力学作为描述量子多体系统长距离长时间行为的有效理论的普遍性，这些主题在未来必然会更频繁地交叉。该项目旨在通过发展物质波湍流领域，在这两个重要主题之间架起一座桥梁。该项目包括一系列科学问题，其中包括观察一种由反向湍流级联的远离平衡的粒子流形成的新形式的冷凝，研究作为波湍流级联耗散源的量子效应，以及调查波湍流中阈值效应的存在。该项目的实验平台是玻色子和费米子原子超流体;这些流体的新形式的强制，耗散和探测将通过利用最近的技术进步来实现，这些技术进步是使用可编程电光设备在原子上形成任意势。这项工作可能提供了解决其他量子动力学问题的蓝图，因为波湍流作为级联激发的一般图像可能与各种量子多体系统的基本激发有关。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical abstractThe understanding of equilibrium phases of quantum matter has enormously progressed in the past decades. The tools of statistical mechanics and linear response theory are well suited to understand the equilibrium and near-equilibrium properties of such phases. This general approach has yielded the most important paradigms and technological breakthroughs in condensed-matter physics of the past century. On the other hand, far-from-equilibrium quantum many-body physics is a frontier in modern physics, and the search for novel paradigms and novel dynamic phases of matter is open and very active. Turbulent states - far-from-equilibrium dynamic states of fields characterized by spatio-temporal chaos - are arguably the least understood of the family of non-equilibrium many-body states. The central scientific goal of this project is to develop the nascent field of matter-wave turbulence as a framework to understand such states and generic far-from-equilibrium quantum dynamics problems. Matter waves of ultracold atoms trapped and controlled in programmable optical potentials offer a near ideal platform for this work. Because quantum technologies are playing an increasingly important role in today’s society, the educational component of this project aims at exposing a broader audience to quantum physics, through lectures series, hands-on workshop and more advanced experiments. Technical abstractFar-from-equilibrium dynamics of both classical and quantum fields almost inevitably leads to turbulent phenomena. However, to date turbulence and quantum dynamics are mostly investigated by separate scientific communities. Given the ubiquity of hydrodynamics as an effective theory to describe the long-distance long-time behavior of quantum many-body systems, these topics are bound to intersect more often in the future. This project aims at providing a bridge between these two important themes by developing the field of matter-wave turbulence. The project consists of a web of scientific issues that include the observation of a novel form of condensation formed from the far-from-equilibrium particle flow of an inverse turbulent cascade, the study of quantum effects as source of dissipation in wave-turbulent cascades, and the investigation of the existence of threshold effects in wave turbulence. The experimental platforms for this project are bosonic and fermionic atomic superfluids; new forms of forcing, dissipation and probing of these fluids will be performed by leveraging recent technical advances in the shaping of arbitrary potentials on atoms using programmable electro-optic devices. This work likely provides blueprints to tackle other quantum dynamics problems because the generic picture of wave turbulence as a cascade of excitations could be relevant to the elementary excitations of various quantum many-body systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.