Chiral Fluids

非技术摘要：材料科学的创新是由物质组织的新范式的引入推动的。这项研究项目涉及一种新的液体的研究，这种液体是由数百万个磁铁--每个磁铁的大小是人类头发的几分之一--旋转形成的。这个桌面模型系统是了解一种新的范式的窗口，这种新范式位于软硬凝聚态物质的交界处，在这种新范式中，材料性质来自于驱动力对元流体微观成分的影响。这种流体打破了新的对称性(时间反转)，使它们具有本项目中探索的新性质。技术摘要：虽然已知拓扑物理可以应用于由旋转组件组成的固体，但时间反转和宇称对称破缺的物理在流体中几乎还没有被开发。研究小组正在使用旋转磁铁系统来创造一种粘性手性流体，其流体动力学描述打破了宇称和时间反转对称性。通过旋转构建块来激活流体在概念上具有欺骗性的简单性，掩盖了这对其性质产生的深刻影响。例如，时间反转对称性的破缺被推测会产生新的输运系数，例如霍尔粘度，这些系数在经典流体的正则处理中是不存在的，但在量子霍尔电子系统和等离子体的理论处理中存在。流体动力学描述的广泛适用性意味着这个项目中的发现超越了它们所进行的具体实验。其目标是阐明可压缩和不可压缩手性流动的物理学，一方面产生基本的见解，另一方面产生设计非平衡流动的新工具。除了科学进步之外，该项目还能够培训学生和本科生，重点是前沿研究中未被充分代表的少数群体。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical Abstract:Innovation in materials science is driven by the introduction of new paradigms for the organization of matter. This research project involves the study of a new kind of liquid formed when millions of magnets - each a fraction of a human hair in size - are made to spin. This table-top model system is a window into a new paradigm sitting at the interface of hard and soft condensed matter, in which the material properties emerge from the effect of drive on microscopic constituents of a meta-fluid. Such fluids break new symmetries (time-reversal) enabling them to have new properties which are explored in this project. Technical Abstract:While it is known that topological physics can be applied to solids built out of rotating components, the physics of time-reversal and parity symmetry breaking remains almost untapped in fluids. The research team is using a system of spinning magnets to create a cohesive chiral fluid whose hydrodynamic description breaks parity and time-reversal symmetries. The deceiving conceptual simplicity of activating a fluid by spinning its building blocks hides the deep consequences this has on its properties. For example, the breaking of time-reversal symmetry is speculated to give rise to new transport coefficients, such as Hall or 'Odd' viscosity, that are absent from canonical treatments of classical fluids but present in theoretical treatments of quantum hall electronic systems and plasmas. The broad applicability of hydrodynamic descriptions means that the discoveries in this project transcend the specific experiments in which they are made. The goal is to elucidate the physics of compressible and incompressible chiral flows, yielding fundamental insights on one hand and a new tool to design out-of-equilibrium meta-fluids on the other. Beyond scientific advances, this project enables training of students and undergraduates, with an emphasis on under-represented minorities in cutting-edge research.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.