Measuring Gravity at the Micron Scale with Laser-Cooled Trapped Microspheres: a Continuation

使用激光冷却捕获微球测量微米级重力：延续

• 批准号: 1806686
• 负责人: Andrew Geraci
• 金额: $ 42万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1806686&HistoricalAwards=false
• 关键词: Measuring; Gravity; Micron; Scale; Laser

This award is supported by the Gravitational Physics and the Atomic, Molecular and Optical Experimental Physics programs. Gravity is by far the least understood fundamental force of nature. One particular mystery has to do with why gravity is so much weaker than the other Standard Model forces in nature. As a number of recent theories have suggested, important clues related to this "hierarchy problem" can be obtained by measuring how gravity behaves at sub-millimeter distances. Such measurements could lead to exciting new discoveries of physics beyond the Standard Model. However, the gravitational force between massive objects becomes weak very rapidly as their size and separation distance decreases, thus making ultra-sensitive measurements a necessity at sub-millimeter length scales. This group is developing an experiment based on new technology which could advance our understanding of gravity by several orders of magnitude at the micrometer length scale. In this approach, a fused silica test mass is suspended in a "container" made of light, leading to greatly reduced friction and enhanced sensitivity. The students and postdoctoral researchers working on this project will be broadly trained in experimental physics and nanofabrication and will be well positioned for entry into the scientific workforce. The fundamental nature of this project appeals to our sense of wonder about the natural world. The nation will benefit from an improved understanding of high-energy physics related to gravitational physics at the micron-length scale, at a fraction of the cost of particle-collider experiments.This award supports an experiment which uses laser-cooled trapped microspheres to test for Yukawa-type deviations from Newtonian gravity at the micron length scale. By optically levitating the force sensor, an exquisite de-coupling from the environment is possible, yielding sub aN-Hz^1/2 force sensitivity at room temperature. This new technique could ultimately advance our understanding of gravity at the micron length scale by a factor of 1,000 to 100,000, and may lead to ground-breaking discoveries. In addition to studies of short-range gravitational forces, the proposed experimental technique will also enable novel investigations of Casimir forces in unexplored regimes. The project is conceptually divided into three tasks: (1) refinement of techniques to position levitated nanospheres within few-micron distances from a source mass surface, (2) investigation of systematic errors in preliminary gravity measurements, (3) in-parallel development of novel methods for trapping and cooling the levitated nanoparticles, including sympathetic cooling with cold atoms. One graduate student, one undergraduate student, and one postdoctoral researcher will be broadly trained in experimental physics and nanofabrication, and encouraged to present results at scientific meetings. By participating in this highly interdisciplinary research project, students will be well equipped for scientific careers. In addition, efforts to include women and minority researchers in the project will be undertaken.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.

该奖项由引力物理和原子、分子和光学实验物理项目支持。到目前为止，万有引力是最不为人所知的自然力。一个特别的谜团与为什么引力比自然界中的其他标准模型力弱得多有关。正如最近的一些理论所表明的那样，通过测量重力在亚毫米距离内的行为，可以获得与这个“等级问题”有关的重要线索。这样的测量可能会带来超越标准模型的令人兴奋的物理学新发现。然而，随着质量物体的大小和间隔距离的减小，它们之间的引力很快就会变得很弱，因此在亚毫米尺度上进行超灵敏测量是必要的。该小组正在开发一项基于新技术的实验，该实验可以在微米长度尺度上将我们对重力的理解提高几个数量级。在这种方法中，熔融二氧化硅测试质量被悬浮在由光制成的“容器”中，从而大大减少了摩擦并提高了灵敏度。从事该项目的学生和博士后研究人员将接受实验物理和纳米制造方面的广泛培训，并将为进入科学大军做好准备。这个项目的基本性质吸引了我们对自然世界的好奇感。国家将受益于对微米尺度上与引力物理相关的高能物理的更好理解，而成本只是粒子对撞机实验的一小部分。该奖项支持一项实验，该实验使用激光冷却的囚禁微球来测试微米尺度上的汤川式牛顿引力偏差。通过光学悬浮力传感器，可以实现与环境的精致解耦，在室温下产生低于AHz^1/2的力灵敏度。这项新技术最终可以将我们对微米尺度重力的理解提高1000到10万倍，并可能导致突破性的发现。除了对短程引力的研究外，拟议的实验技术还将使对未知区域中的卡西米尔力进行新的研究成为可能。该项目从概念上分为三项任务：(1)改进在距源质量表面几微米距离内定位悬浮纳米球的技术；(2)调查初步重力测量中的系统误差；(3)同时开发捕获和冷却悬浮纳米球的新方法，包括用冷原子进行共振冷却。一名研究生、一名本科生和一名博士后研究员将接受实验物理和纳米制造方面的广泛培训，并鼓励他们在科学会议上展示成果。通过参与这一高度跨学科的研究项目，学生们将为科学生涯做好准备。此外，还将努力将女性和少数族裔研究人员纳入该项目。这一奖项反映了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。

项目成果

Searching for Ultralight Dark Matter with Optical Cavities

• DOI: 10.1103/physrevlett.123.031304
• 发表时间: 2019-07-17
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Geraci, Andrew A.;Bradley, Colin;Derevianko, Andrei
• 通讯作者: Derevianko, Andrei

Searching for new physics using optically levitated sensors

• DOI: 10.1088/2058-9565/abcf8a
• 发表时间: 2021-01-01
• 期刊: QUANTUM SCIENCE AND TECHNOLOGY
• 影响因子: 6.7
• 作者: Moore, David C.;Geraci, Andrew A.
• 通讯作者: Geraci, Andrew A.

Mechanical quantum sensing in the search for dark matter

• DOI: 10.1088/2058-9565/abcfcd
• 发表时间: 2021-04-01
• 期刊: QUANTUM SCIENCE AND TECHNOLOGY
• 影响因子: 6.7
• 作者: Carney, D.;Krnjaic, G.;Zhao, Y.
• 通讯作者: Zhao, Y.