Quantum Coherent Applications of Superfluid 3He

超流体 3He 的量子相干应用

• 批准号: 2210112
• 负责人: William Halperin
• 金额: $ 65.53万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2210112&HistoricalAwards=false
• 关键词: Quantum; Coherent; Applications; Superfluid; 3He

Nontechnical Description:There are two important challenges today where physics plays an essential role. The first is to develop a new generation of computers that can handle the complexity and vastness of the digital information age. These putative quantum computers take advantage of quantum states of matter which contain information that can be stored and manipulated at sufficiently low temperature that neither thermal fluctuations nor impurities destroy their coherence. One important class of such quantum states is a robust form of superconductivity which does not have mirror symmetry and is called chirality, analogous to twisted strands of DNA. The paradigm quantum material having this property is superfluid 3He. Investigation in this project of quantum coherence in 3He tests a fundamental prediction that the anomalous thermal Hall can provide an unambiguous identification of chirality in any superconductor that is a candidate material for quantum computation. There is a second challenge. Our universe appears to be missing 70% of its mass, so-called dark matter. Dark matter is unobserved except for its gravitational impact on star distributions in galaxies. Its absence from all other observation is an existential problem. Many attempts have been launched to develop high resolution sensing tools to identify this missing mass as it floods throughout our environment. A possible detector is based on high coherence of i nuclear spin precession states in superfluid 3He. Its known coherence makes it a very attractive choice for this purpose; yet the limits of coherence have not yet been fully explored. A second unique benefit of 3He spin precession for mass sensing, is its tunability allowing continuous measurements in situ to be made over a wide range of dark mass.Technical Description:Superfluid helium-three is a known topological quantum condensed system, a model for understanding complex quantum materials and in particular, odd-parity chiral superconductors; a subject of interest to researchers in the burgeoning field of quantum information science. The project Quantum Coherent Applications of Superfluid 3He, is a platform to improve and demonstrate quantum coherence among chiral quantum systems including superconducting quantum materials. Additionally, these materials provide an opportunity for instrumentation development based on quantum sensing. One such important application addresses the existential problem, how to determine the nature of dark matter. For superfluid 3He, the paradigm system of choice, the quantum degrees of freedom are its nuclear spin and orbital angular momentum coherently manifest on a macroscopic scale. Superfluid 3He imbibed into very high porosity (98%) uniformly anisotropic silica aerogel controls both the spin and orbital angular momentum quantization axes. Using nuclear magnetic resonance, the directions of these axes can be unambiguously determined. Recent theory predicts that observation of a non-zero thermal Hall effect in the superfluid in uniformly anisotropic silica aerogel defines the chiral axis perpendicular to a thermal gradient. Confirmation of this theory provides a unique tool, measurement of the transverse thermal conductance, that can be used to determine chirality. The application extends to superconducting materials relevant to quantum information science. Quantum sensing is a second application in this project. The long-lived, quantum-spin coherent state of superfluid 3He provides a promising detector for light dark matter. Importantly, in this case high sensing sensitivity is combined with the advantage of continuous tuning for the putative dark mass, thereby at the very least establishing limits on galactic axion production, an existential problem in modern physics. Key to this project is its partnership with theoretical physicists in both the fields of superfluid 3He and dark matter, together with cryogenic and nuclear magnetic resonance spectroscopy expertise at Northwestern.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.

非技术描述：今天有两个重要的挑战，物理学在其中发挥着至关重要的作用。第一个目标是开发新一代计算机，使其能够处理数字信息时代的复杂性和广阔性。这些假定的量子计算机利用了物质的量子态，这些量子态包含可以在足够低的温度下存储和操作的信息，热波动和杂质都不会破坏它们的相干性。其中一类重要的量子态是一种坚固的超导形式，它不具有镜像对称性，被称为手性，类似于DNA的扭曲链。具有这种性质的典型量子材料是超流体3 He。在这个项目中，3 He的量子相干性的研究测试了一个基本的预测，即反常的热霍尔可以提供一个明确的识别任何超导体中的手征性，这是一个候选材料的量子计算。还有第二个挑战。我们的宇宙似乎缺少了70%的质量，即所谓的暗物质。暗物质除了对星系中星星分布的引力影响外，是不可观测的。它在所有其他观察中的缺席是一个存在性问题。人们已经进行了许多尝试，以开发高分辨率的传感工具，以识别这种缺失的质量，因为它充斥着我们的环境。一种可能的探测器是基于超流3 He中i核自旋旋进态的高相干性。其已知的连贯性使其成为一个非常有吸引力的选择，为此目的，但连贯性的限制尚未得到充分探讨。第二个独特的好处3 He自旋旋进的质量传感，是它的可调性允许连续测量原位在很大范围内的暗mass.Technical Description：超流氦-3是一个已知的拓扑量子凝聚系统，一个模型，用于理解复杂的量子材料，特别是奇宇称手性超导体;一个感兴趣的课题，研究人员在新兴领域的量子信息科学。超流3 He的量子相干应用项目是一个平台，旨在改善和展示包括超导量子材料在内的手性量子系统之间的量子相干性。此外，这些材料为基于量子传感的仪器开发提供了机会。这样一个重要的应用解决了存在的问题，如何确定暗物质的性质。对于超流3 He，选择的范例系统，量子自由度是其核自旋和轨道角动量在宏观尺度上相干地表现出来。超流3 He吸入非常高的孔隙率（98%）均匀各向异性的二氧化硅气凝胶控制自旋和轨道角动量量子化轴。使用核磁共振，这些轴的方向可以明确地确定。最近的理论预测，在均匀各向异性的二氧化硅气凝胶中的超流体中观察到的非零热霍尔效应定义了垂直于热梯度的手征轴。这一理论的证实提供了一个独特的工具，测量的横向热导，可以用来确定手性。该应用扩展到与量子信息科学相关的超导材料。量子传感是该项目的第二个应用。超流3 He的长寿命量子自旋相干态为光暗物质提供了一个有前途的探测器。重要的是，在这种情况下，高传感灵敏度与连续调谐假定的暗物质的优势相结合，从而至少建立了银河系轴子生产的限制，这是现代物理学中存在的问题。该项目的关键是与超流氦3和暗物质领域的理论物理学家的合作，以及西北大学的低温和核磁共振光谱学专业知识。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Axion Wind Detection with the Homogeneous Precession Domain of Superfluid Helium-3

利用超流 Helium-3 的均匀进动域进行轴子风探测

• DOI: 10.1103/physrevlett.129.211801
• 发表时间: 2022
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Gao, Christina;Halperin, William;Kahn, Yonatan;Nguyen, Man;Schütte-Engel, Jan;Scott, John William
• 通讯作者: Scott, John William

Planar Aerogel and Superfluid 3He, Structure and Transitions

平面气凝胶和超流体 3He，结构和转变

• DOI: 10.1007/s10909-024-03069-2
• 发表时间: 2024
• 期刊: Journal of Low Temperature Physics
• 影响因子: 2
• 作者: Scott, J. W.;Nguyen, M. D.;Park, D.;Halperin, W. P.
• 通讯作者: Halperin, W. P.