Compressible Turbulence from Quantum to Classical

要想使核聚变成为一种能量来源，提高超音速飞行能力，并解释超新星和中子星碰撞产生的金等元素的形成，就需要对湍流有深入的了解。尽管它很重要，但湍流的许多方面仍然没有得到很好的理解，部分原因是由于进行实验的困难：例如，研究超音速流动需要昂贵的风洞，中子星只能间接测量。虽然美国国家科学基金会资助的LIGO等项目正在努力研究这些系统，但冷原子技术的最新进展为在桌面实验中制造湍流提供了一个新的平台。例如，超流体冷原子具有非常低的声速，可以实现高超音速流动，并且具有高度可调性，可以直接模拟中子星的各个方面。该项目将在这些桌面实验中的量子湍流与补充核物理学、核天体物理学和经典湍流的重要应用之间建立联系。这些成果不仅将推动科学进步，而且将确定独特的量子特征，这些特征可用于推进量子技术，并带来未来的社会效益，类似于先前冷原子技术的进步产生了使GPS成为可能的精确时钟。本项目将探索量子与经典流体力学之间的关系，解决有关湍流微观起源的问题，以及如何从微观物理中产生中子星等模型所需的宏观流体力学。具体来说，它将探索这些宏观理论是如何在粗粒量子系统之后出现的，回答这样的问题：新兴理论是经典的（即它们是否流向一个类似于纳维-斯托克斯的不移点？）还是它们保留了独特的量子效应，可以用于新的应用？在破坏性成像的情况下，将开发检测和表征量子湍流的方法，并将在与实验小组的密切合作中进行验证，探索新的量子现象。然后，这些经过验证的方法将用于推进核物理学，例如脉冲星故障的起源。这些调查需要高性能计算和复杂的数据分析技术，这将导致开源工具，广泛影响各种相关领域，并为学生提供成功的科学事业所需的技能。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

A deep understanding of turbulence is required to enable fusion as a source of energy, improve supersonic flight, and explain the formation of elements like gold from supernovae and colliding neutron stars. Despite its importance, many aspects of turbulence are still not well understood, in part due to the difficulty of performing experiments: for example, studying supersonic flow requires expensive wind tunnels, and neutron stars can only indirectly be measured. While efforts are underway to study these systems through NSF funded programs like LIGO, recent advances in cold-atom technology provide a new platform to create turbulence in table-top experiments. For example, superfluid cold atoms have a very low speed of sound, enabling hypersonic flow, and are highly tunable, allowing them to directly model aspects of neutron stars. This project will establish a connection between quantum turbulence in these table-top experiments and important applications that complement ongoing efforts in nuclear physics, nuclear astrophysics, and classical turbulence. The outcomes will not only progress science, but will identify unique quantum features that can be used to advance quantum technologies with future societal benefit similar to how previous advances in cold atom technology produced the precision clocks that enable GPS.This project will explore the relationship between quantum and classical hydrodynamics, addressing questions about the microscopic origins of turbulence, and how the macroscopic hydrodynamics needed to model neutron stars etc. emerge from microscopic physics. Specifically, it will explore how these macroscopic theories emerge after coarse-graining quantum systems, answering questions like: Are the emergent theories classical (i.e. do they flow to a Navier-Stokes-like fixed-point?) or do they retain unique quantum effects that can be exploited for new applications? Methods will be developed for detecting and characterizing quantum turbulence in spite of destructive imaging, and will be validated in close collaboration with experimental groups, exploring new quantum phenomena along the way. These validated methods will then be used to advance nuclear physics such as the origin of pulsar glitches. These investigations require high performance computing and sophisticated data analysis techniques, which will result in open source tools, broadly impacting a variety of related fields, and provide students with the skills needed for successful careers in science.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.