3He in Confinement

非技术摘要：在非常低的温度下，所有物质都进入一个仅由量子力学描述的区域，其中物质的状态被称为量子态。其中一些状态允许电子电流完全无摩擦地流动，在氦液体中，原子可以流动而不产生任何热量，因此被称为超流体。在这个项目中，利用项目实验室制备的极小尺寸的多孔玻璃，在各向异性限制下设计了新类型的氦的轻同位素超流体氦-3。这些状态的拓扑结构允许存储量子信息，而量子信息是量子计算的重要组成部分，有望引发计算机技术革命。低温和量子态的拓扑结构都是必不可少的。研究生和本科生以及一些高中生学习制造多孔玻璃材料所需的专门技术，并使用扫描电子显微镜、低温和光学方法对其进行表征，以实现项目目标：创建和识别液氦的新拓扑量子态。还提供了高质量的样品，供与美国、法国、日本和英国的其他实验室合作，用于量子流体的一系列研究应用。此外，我们网站上的一个基于主动软件的工具是由研究生开发和维护的，以使我们研究的超流体的物理性质变得易懂。国际和平协会继续倡导公众认识到氦是一种宝贵的自然资源，为最近召开的APS、ACS和MRS赞助的氦经济委员会服务，并在国会、国家电视台、科学杂志以及国际会议和研讨会上的特邀演讲中露面。技术摘要：这项研究生研究项目包括在各种可能的费米波3He超流体中寻找具有工程对称性的新量子态。氧化铝膜中致密的小孔阵列中的纳米结构环境被用来定义特定的各向异性环境，并冷却到超低温，用于使用超声波和高分辨率核磁共振进行研究。该项目的第二部分是使用高孔隙率的二氧化硅气凝胶，这种气凝胶是以受控的各向异性制造的。用这种方法检验了最近对这种新物质状态的预测，特别是具有手性和非手性对称性的状态之间的相互作用。这种超流体的拓扑结构支持作为量子信息处理的关键组成部分的Majorana激发，并且与拓扑超导体有直接的联系。该理论的一个核心方面是，各向异性环境可以稳定各向异性超流状态。在超流3He中已经有了类似于拓扑超导体UPt3的行为的迹象。在该项目的研究中，表面条件的控制是使用玻色超流4He的单原子层来实现的。此外，声谐振腔是利用纳米制造设施制造的。该项目支持继续资助研究生教育和实验物理本科生研究。

Nontechnical Abstract:At very low temperatures all matter enters a regime described only by quantum mechanics where the states of matter are called quantum states. Some of these states allow electron currents to flow that are completely frictionless and in helium liquids the atoms can flow without generating any heat, and are called superfluids. In this project new classes of the superfluid of the light isotope of helium, helium-three, are engineered in anisotropic confinement using extremely small-scale porous glass prepared in the project laboratory. The topology of these states allows storage of quantum information which is an essential component of the quantum calculations that promise a revolution in computer technology. Both the low temperatures and the topology of the quantum states are essential. Graduate students and undergraduates, as well as some high school students, learn the specialized techniques that are required to make the porous glass materials and characterize them using scanning electron microscopy, cryogenics, and optical methods to achieve the project goals: creating and identifying new topological quantum states of liquid helium. High quality samples are also provided for collaborations with other laboratories in the USA, France, Japan, and the United Kingdom for a range of research applications on quantum fluids. Furthermore, an active software based tool on our website is developed and maintained by graduate students, to make accessible the physical properties of the superfluids we study. The PI continues advocacy for public awareness of helium as a precious natural resource serving on the recently convened APS, ACS, and MRS sponsored Helium Economics Committee, and appearances before congress, on national television, for science magazines, and at invited talks at international conferences and workshops. Technical Abstract:This project for graduate student research includes the search for new quantum states with engineered symmetry among the manifold of possible fermionic p-wave 3He superfluids. Nano-structured environments from dense arrays of small pores in alumina membranes are used to define specific anisotropic environments and cooled to ultra-low temperatures for investigation using ultra-sound and high resolution NMR. A second part of the project is to use high porosity silica aerogel that is fabricated with controlled anisotropy. With this approach the recent predictions for such new states of matter are tested, particularly the interplay of states with chiral and non-chiral symmetry. The topology of such superfluids support Majorana excitations that have been proposed as a key component of quantum information processing and has a direct connection to topological superconductors. A central aspect of the theory is that anisotropic environments can stabilize anisotropic superfluid states. There is already an indication of this in superfluid 3He that parallels the behavior of the topological superconductor UPt3. In the project's research control of the surface conditions are performed using single atom layers of the bosonic superfluid 4He. Additionally, acoustic resonant cavities are produced using nanofabrication facilities. The project supports continuing funding for graduate education and undergraduate research in experimental physics.