3He in Confinement

3他在监禁中

• 批准号: 1602542
• 负责人: William Halperin
• 金额: $ 46.25万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-02-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1602542&HistoricalAwards=false
• 关键词: 3He; Confinement

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.

非技术摘要：在非常低的温度下，所有物质都进入了一个仅由量子力学描述的制度，而物质状态称为量子状态。 这些状态中的一些允许电子电流完全无摩擦，在氦气液体中可以流动，而无需产生任何热量，被称为超流体。 在这个项目中，使用在项目实验室中制备的极小小规模的多孔玻璃，在各向异性限制中设计了氦轻型同位素超级流体的新类别。这些状态的拓扑允许存储量子信息，这是有望在计算机技术中进行革命的量子计算的重要组成部分。量子状态的低温和拓扑都是必不可少的。研究生和本科生以及一些高中生，学习了制造多孔玻璃材料并使用扫描电子显微镜，低温和光学方法来实现项目目标所需的专业技术：创建和识别新的液体液体式拓扑量子状态。 还提供了与美国，法国，日本和英国的其他实验室合作的高质量样本，以涉及量子流体的一系列研究应用程序。 此外，研究生开发和维护了基于活跃的软件工具，以使我们研究的超流体的物理特性可访问。 PI继续倡导公众对氦气的认识，作为最近召集的APS，ACS和夫人赞助的氦气经济学委员会，以及国会，国家电视台，《科学杂志》和国际会议上的邀请演讲。技术摘要：研究生研究的项目包括在可能的费米斯P-Wave 3HE超级流体的流形中搜索具有工程对称性的新量子状态。氧化铝膜中小毛孔的密集阵列的纳米结构环境用于定义特定的各向异性环境，并冷却至超低温度，以使用超声波和高分辨率NMR进行研究。 该项目的第二部分是使用用受控各向异性制造的高孔隙率硅胶。 通过这种方法，对这种新物质状态的最新预测进行了测试，尤其是与手性和非手续对称性状态的状态相互作用。 此类超流体的拓扑支持Majorana激发，这些激发是量子信息处理的关键组成部分，并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体状态。 在超氟3e中已经有一个迹象表明，与拓扑超导体UPT3的行为相似。 在项目的研究控制中，对表面条件进行了使用，使用骨化超氟4HE的单个原子层进行。 此外，使用纳米制作设施产生声音谐振腔。该项目支持持续用于研究生教育和实验物理学本科研究的资金。