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。万有引力是迄今为止最不为人所知的自然基本力量。一个特别的谜团是，为什么引力比自然界中其他标准模型的力弱得多。正如许多最近的理论所提出的那样，与这个“层次问题”相关的重要线索可以通过测量引力在亚毫米距离上的行为来获得。这样的测量可能会导致超出标准模型的令人兴奋的物理学新发现。然而，随着大质量物体的尺寸和分离距离的减小，它们之间的引力会迅速减弱，因此需要在亚毫米尺度上进行超灵敏的测量。这个小组正在开发一项基于新技术的实验，该实验可以将我们对重力的理解在微米长度尺度上提高几个数量级。在这种方法中，一个熔融的二氧化硅测试块悬浮在一个由光制成的“容器”中，从而大大减少了摩擦，提高了灵敏度。参与该项目的学生和博士后研究人员将在实验物理和纳米制造方面接受广泛的培训，并为进入科学队伍做好准备。这个项目的基本性质吸引了我们对自然世界的好奇感。这个国家将受益于在微米尺度上对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捕获微球在微米尺度上测试与牛顿引力的汤川型偏差。通过光学悬浮力传感器，可以实现与环境的精确解耦，在室温下产生低于an - hz ^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，并可能带来突破性的发现。除了对短程引力的研究，提出的实验技术还将使对未开发地区的卡西米尔力的新研究成为可能。该项目在概念上分为三个任务：(1)改进悬浮纳米球在距离源质量表面几微米距离内的定位技术；(2)调查初步重力测量中的系统误差；(3)并行开发捕获和冷却悬浮纳米粒子的新方法，包括冷原子的共感冷却。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发表研究成果。通过参与这个高度跨学科的研究项目，学生将为科学事业做好准备。此外，还将努力将妇女和少数民族研究人员纳入该项目。该奖项反映了美国国家科学基金会的法定使命，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

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.