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.

该奖项得到了重力物理学和原子，分子和光学实验物理学计划的支持。了解微观距离处的重力性质是基本物理学中最重要的开放问题之一。尽管一般相对论提供了一个经过良好测试的框架来描述大距离的重力效应，但不能与粒子物理的标准模型一致地结合使用，以在小尺度上提供重力描述。可以纳入标准模型的重力理论的发展是基本物理学的核心目标，对我们对粒子物理学的理解以及似乎渗透到宇宙的“暗能量”的神秘性质具有广泛的影响。许多试图为重力提供一致的显微镜框架（例如，涉及额外维度的理论）预测，重力可能会偏离熟悉的反平方法，而距离短于MM。由于显微镜距离处的重力相互作用的较小强度，这种偏差极为难以在实验中测量。这里描述的研究试图通过新颖的实验设置来了解微观引力力的领域。此外，这项研究将增强对国家未来至关重要的STEM区域的培训。这些距离尺度的预览测量采用了从人类大小的设备中得出的技术，在该设备中，将机械弹簧用作力传感器。该组使用激光的光场开发了一种急剧的新技术，以限制和测量微米（或最终是亚sibsiron）尺寸石英微球的运动。该小组进行的先前研究包括迄今为止最敏感的搜索，该搜索比电子电荷小4个数量级以上的电荷。这是必须排放微球并检查它们是否确实中立的副产品。该小组已经完成了一个新的陷阱的构建，在该陷阱中，整个微球位置读数都是经过干预进行的。这是研究领域的第一个，将适用于其他领域，例如生物学或聚合物科学。该赠款支持的研究包括探索旋转微球的可能性，可以减少重力测量的背景，并可能导致纳米近镜的发展。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力和更广泛影响的评估来评估CRITERIA的评估。

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