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Understanding Gravity at the Smallest Scale

了解最小尺度的重力

基本信息

批准号：
1802952
负责人：
Giorgio Gratta
金额：
$ 40万
依托单位：
Stanford 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：
2018-05-01 至 2021-04-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1802952&HistoricalAwards=false
关键词：
Understanding Gravity Smallest Scale

项目摘要

This award is supported by the Gravitational Physics and the Atomic, Molecular and Optical Experimental Physics programs. Understanding the nature of gravity at microscopic distances is one of the most important open problems in fundamental physics. Although General Relativity provides an extremely well-tested framework for describing gravitational effects at large distances, it cannot be consistently combined with the Standard Model of particle physics to provide a description of gravity at small scales. The development of a quantum theory of gravity that can be incorporated into the Standard Model is a central goal of fundamental physics, with broad implications for our understanding of particle physics and the mysterious nature of the "dark energy" that appears to permeate the universe. Many theories attempting to provide a consistent microscopic framework for gravity (e.g., those involving extra dimensions) predict that gravity could deviate from the familiar inverse square law at distances shorter than a mm. Such deviations are extremely difficult to measure experimentally due to the small strength of gravitational interactions at microscopic distances. The studies described here attempt to gain insights into the realm of microscopic gravitational forces with a novel experimental setup. Additionally, the research will enhance the training of students in STEM areas which are vital for the future of the nation.Previous measurements at these distance scales have employed techniques derived from human-size devices in which mechanical springs are used as force sensors. This group has developed a drastically new technique, using the light field of a laser to confine and measure the motion of micron (or, eventually, submicron)-size quartz microsphere. Previous studies undertaken by this group include the most sensitive search to date for fractional charges over 4 orders of magnitude smaller than the charge of an electron. This is a by-product of having to discharge the microspheres and check that they are really neutral. The group has completed the construction of a new trap in which the entire microsphere position readout is carried out interferometrically. This is a first in this area of research and will be applicable to other areas, e.g. biology or polymer science. The studies supported by this grant include exploring the possibility of spinning the microspheres, something that could reduce the background of the gravity measurements and may also lead to the development of nanogyroscopes.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计划支持。在微观距离上理解引力的本质是基础物理学中最重要的开放性问题之一。虽然广义相对论提供了一个非常好的框架来描述大距离的引力效应，但它不能与粒子物理学的标准模型相结合来描述小尺度的引力。发展一个可以被纳入标准模型的量子引力理论是基础物理学的一个中心目标，对我们理解粒子物理学和似乎渗透在宇宙中的“暗能量”的神秘性质具有广泛的影响。许多理论试图为引力提供一个一致的微观框架（例如，那些涉及额外维度的理论）预测，在小于1毫米的距离上，引力可能偏离熟悉的平方反比定律。由于在微观距离上引力相互作用的强度很小，这种偏离极难通过实验测量。这里描述的研究试图通过一种新颖的实验装置来深入了解微观引力领域。此外，该研究将加强对STEM领域学生的培训，这对国家的未来至关重要。以前在这些距离尺度上的测量采用了来自人体大小的设备的技术，其中机械弹簧被用作力传感器。这个小组开发了一种全新的技术，利用激光的光场来限制和测量微米（或最终亚微米）尺寸的石英微球的运动。这个小组以前进行的研究包括迄今为止对比电子电荷小4个数量级以上的部分电荷的最灵敏的搜索。这是必须对微球放电并检查它们是否真的是中性的副产品。该小组已经完成了一个新的陷阱的建设，其中整个微球的位置读出进行干涉。这是该研究领域的第一次，并将适用于其他领域，例如生物学或聚合物科学。该基金支持的研究包括探索旋转微球的可能性，这可以减少重力测量的背景，也可能导致纳米陀螺仪的发展。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

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Electrically driven, optically levitated microscopic rotors

DOI：
10.1103/physreva.99.041802
发表时间：
2018-12
期刊：
Physical Review A
影响因子：
2.9
作者：
Alexander D. Rider;Charles P. Blakemore;A. Kawasaki;N. Priel;Sandip Roy;G. Gratta
通讯作者：
Alexander D. Rider;Charles P. Blakemore;A. Kawasaki;N. Priel;Sandip Roy;G. Gratta

High sensitivity, levitated microsphere apparatus for short-distance force measurements

DOI：
10.1063/5.0011759
发表时间：
2020-08-01
期刊：
REVIEW OF SCIENTIFIC INSTRUMENTS
影响因子：
1.6
作者：
Kawasaki, Akio;Fieguth, Alexander;Gratta, Giorgio
通讯作者：
Gratta, Giorgio

Precision Mass and Density Measurement of Individual Optically Levitated Microspheres

DOI：
10.1103/physrevapplied.12.024037
发表时间：
2019-02
期刊：
Physical Review Applied
影响因子：
4.6
作者：
Charles P. Blakemore;Alexander D. Rider;Sandip Roy;A. Fieguth;A. Kawasaki;N. Priel;G. Gratta
通讯作者：
Charles P. Blakemore;Alexander D. Rider;Sandip Roy;A. Fieguth;A. Kawasaki;N. Priel;G. Gratta

Three-dimensional force-field microscopy with optically levitated microspheres

具有光学悬浮微球的三维力场显微镜