Quantum Hydrodynamics and Energy Flow in Fermi Gases

这个项目使用激光闪光摄影来成像几乎无摩擦的流体流动和一种独特的超冷原子气体的能量流动，这种气体被限制在由激光制成的薄片之间。这种特殊的原子气体具有“强相互作用”和“费米子”的特性，这使得它在许多方面表现得像液态金属。当两团原子碰撞时，它们会相互反弹，产生冲击波。这些实验模拟了原子物理学之外的智力学科中奇异物质的特性，包括中子星和夸克-胶子等离子体，它们在大爆炸后几微秒内就存在了。实验还测试了超高温超导体的理论，超导体的工作温度远高于室温，可以实现节能电力线和磁悬浮列车。该项目提供了一个理想的学习机会，并有助于培养本科生、研究生和博士后助理，他们在一个支持PI的环境中作为一个团队来设计、构建和执行新的实验，并对结果进行理论分析。通过这种广泛的培训，毕业生和博士后助理将很好地成为解决科学和工程领域出现的研究问题的领导者。该项目将研究被困在设计光学势中的6Li原子的费米气体中的流体动力学输运和能量流。电势将通过数字微镜装置（DMD）成像到云上，以控制原子气体密度和温度的空间分布。将原子限制在两个排斥片电位之间，可以在垂直于片的视线方向上以几乎恒定的原子密度进行原位成像。这抑制了在水动力和低密度弹道区域测量柱密度的不必要的平均，这一直困扰着以前的研究。由于相互作用强度可调，该方法为探索跨学科边界的概念提供了新的机会，包括尺度不变系统的局部输移性质、不同温度下尺度不变系统之间准稳态能量流动的保形场论预测，以及强相互作用流体中的激波形成。该项目的目标包括现场测量i)一维流体动力流动，局部剪切粘度和导热系数；ii)不同温度下两种尺度不变云之间的能量流动；iii)冲击波形成与相互作用强度、温度和密度的关系。

This project uses laser flash photography to image the nearly frictionless fluid flow and energy flow of a unique ultra-cold atomic gas confined between sheets made of laser light. This special atomic gas has the properties of being "strongly interacting," and "fermionic" which causes it to behave in many ways like a liquid metal. When two clouds of these atoms collide, they bounce off of one another, creating shock waves. These experiments simulate properties of exotic matter in intellectual disciplines well outside atomic physics, including neutron stars and quark-gluon plasmas, which existed microseconds after the Big Bang. The experiments also test theories of super-high temperature superconductors, which operate far above room temperature, enabling energy-saving power lines and magnetically levitated trains. The project provides an ideal learning opportunity and serves to train undergraduate students, graduate students, and post-doctoral associates, who work as a team in a supportive environment with the PI to devise, construct, and perform new experiments, and to theoretically analyze the results. With this broad training, graduating students and post-doctoral associates are well situated to be leaders in tackling research questions that arise in science and engineering. This project will study hydrodynamic transport and energy flow in a Fermi gas of 6Li atoms trapped in designer optical potentials. The potentials will imaged onto the cloud from a digital micro-mirror device (DMD) to control the spatial profiles of the atomic gas density and temperature. Confining the atoms between two repulsive sheet potentials enables in-situ imaging with nearly constant atom density along the line-of-sight direction perpendicular to the sheets. This suppresses unwanted averaging of the measured column density over hydrodynamic and low density ballistic regions, which has plagued previous studies. With tunable interaction strength, this method offers new opportunities to explore concepts that cross interdisciplinary boundaries, including local transport properties of scale-invariant systems, recent conformal field theory predictions of quasi-steady state energy flow between scale-invariant systems at different temperatures, and shock wave formation in strongly interacting fluids. The goals of this project include in-situ measurements of i) 1D hydrodynamic flow, local shear viscosity and thermal conductivity; ii) Energy flow between two scale-invariant clouds at different temperatures; iii) Shock wave formation versus interaction strength, temperature, and density profiles.