Engineering New Anisotropic Superfluid Phases of 3He

非技术性摘要：拟议的项目突出了两名研究生的研究性培训。它包括一名当地高中生目前参与开发最先进的软件，对小学和当地高中的学生团队进行科学教育，以及一名本科生正在进行的研究项目，为新一代核物理实验开发新型探测仪器。这些活动是PI的二氧化硅气凝胶生长实验室的产物，并由其实现。一个成功的故事涉及三个年轻的7年级女孩，她们学习种植硅醇，这是一项科学比赛的一部分，该比赛赢得了州和全国地区冠军。本项目支持这一教育项目，并得到国际学生联合会和他的研究生团队的指导。事实上，研究项目的核心部分集中在气凝胶内的量子流体，气凝胶是一种极其多孔的玻璃，用于在超低温下设计超流氦的新量子态，这是该项目的关键组成部分。低温研究和技术在当今量子世界的重要性在于，它推动了仪器的发展，推动了温度极限的降低，PI的实验室在这方面做出了重大贡献。这项工作提供了对实验凝聚态物理中训练有素的博士后和新教师任命的需求，并激发了对具有许多身体物理、复杂对称破缺和量子相变背景的年轻科学家的招募。对超流氦-3范式的研究为解决当今一些具有挑战性的科学问题提供了指导，从量子信息科学中的量子比特相干到材料物理。技术摘要：超流氦-3是一个已知的拓扑量子凝聚系统，预计它将以准粒子束缚态的形式存在Majorana费米子激发，这是量子信息科学领域研究人员感兴趣的课题。这项名为《设计新的氦-3各向异性超流相》的计划是基础研究和仪器开发的平台。今天，人们已经知道，通过将超流体限制在高度多孔、各向异性、气凝胶或薄膜中，通过工程各向异性来稳定具有不同自发破缺对称性的新型氦-三种超流体相是可能的。每一相都有其特定类型的轨道和/或自旋拓扑奇点，包括其轨道和自旋角动量的涡旋和超流体结构。据预测，超流B相的表面和超流A相中的涡核(后者是手性相)将蕴藏着量子信息科学研究人员强烈感兴趣的马约拉纳费米子。在这种情况下，手性是镜像对称性的丧失和时间反转对称性的破坏的组合，这是拓扑超导的一个关键性质。在所提出的工作中，利用核磁共振和共振声腔技术，在较宽的磁场和温度范围内研究了超流氦-3的新的各向异性相。最近在PI实验室取得的成功，就是能够将温度持续保持在0.001 K以下，长达几个月。这些极其高效的冰箱允许在长时间尺度上保持量子相干性，并提供了提高量子比特性能的机会，这是量子信息处理的基本要求。初步的结果对于理解各向异性和磁场的异常相互作用是有希望的。这项研究的一个方面是预测在拓扑超流体氦-3-B的自由表面上的Majorana费米子的拓扑热力学相变。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: The proposed project highlights research training of two graduate students. It includes current participation of one local high school student developing state-of-the-art software, science education of student teams from elementary school and from a local high school, and an ongoing research project of an undergraduate student to develop a novel detection instrument for a new generation of nuclear physics experiments. These activities are outgrowths of, and made possible by, the PI's silica aerogel growth laboratory. One success story involves three young 7th grade girls who learned to grow silica alcogels as part of a science competition that won state and then national-regional championships. The present project supports this educational program with mentoring from the PI and his graduate student team. In fact, the central part of the research project is focused on quantum fluids confined within aerogel, an extremely porous glass used to engineer new quantum states of superfluid helium at ultra-low temperatures, a key component of the project. The importance of low temperature research and technology in today's quantum world is that it drives development of instrumentation, pushing limits in temperature ever lower, where the PI's laboratory has made significant contributions. This work supplies a need for trained postdocs and new faculty appointments in experimental condensed matter physics and inspires recruitment of young scientists with background in many body physics, complex symmetry breaking, and quantum phase transitions. Investigation of the superfluid helium-three paradigm provides guidance for solutions to some of the challenging scientific problems of the day, ranging from qubit coherence in quantum information science to materials physics. Technical Abstract: Superfluid helium-three is a known topological quantum condensed system that is predicted to host Majorana fermionic excitations in the form of quasiparticle bound states, a subject of interest to researchers in the field of quantum information science. The proposal, Engineering New Anisotropic Superfluid Phases of Helium-three, is a platform for both basic research and instrumentation development. Today it is known that it is possible to stabilize new types of helium-three superfluid phases exhibiting different spontaneously-broken symmetries by engineering anisotropy through confinement of the superfluid in highly porous, anisotropic, aerogels or in thin films. Each phase has its specific type of orbital and/or spin topological singularities including vortices and superfluid textures of its orbital and spin angular momenta. The surface of the superfluid B-phase, and the vortex cores in the superfluid A-phase, the latter being a chiral phase, are predicted to harbor Majorana fermions of intense interest to researchers in quantum information science. Chirality, in this context, is the combination of loss of mirror symmetry in conjunction with broken time-reversal symmetry, a key property of topological superconductivity. In the proposed work new anisotropic phases of superfluid helium-three are investigated using nuclear magnetic resonance and resonant acoustic cavity techniques for a wide range of magnetic field and temperature. Recent success in the PI's laboratory on which the proposed program builds, is the capability of continuously holding temperatures below 0.001 K, for as long as several months. These extremely efficient refrigerators allow maintenance of quantum coherence over long time scales and offer opportunities for improvement in qubit performance, an essential requirement for quantum information processing. Preliminary results are promising for understanding the unusual interplay of anisotropy and magnetic field. One aspect of this research is motivated by prediction of a topological thermodynamic phase transition of Majorana fermions at the free surface of topological superfluid helium-three-B.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.