Understanding and Reducing Thermal Noise via Atomistic Simulations

通过原子模拟了解和减少热噪声

• 批准号: 1404110
• 负责人: Hai-Ping Cheng
• 金额: $ 31.5万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1404110&HistoricalAwards=false
• 关键词: Understanding; Reducing; Thermal; Noise; via

The research project is a computational oriented theoretical effort that aims at understanding the physical origin of thermal noise in optical coating materials at the atomic level and providing guidance for the optimal ratio of metallic elements in composite amorphous oxides (silica, titania, tantala, hafnia etc). Thermal noise that is caused by atomic movement at finite temperature affects the performance of ultra high-resolution interferometers such as the laser interferometer employed in the Laser Interferometer Gravitational-Wave Observatory (LIGO) and is of special interest to the LIGO Scientific Collaboration (LSC). The project will provide rigorous training for graduate students in computational physics. The PI has collaborations with a number of international experimental and computational materials physics groups including a group at Glasgow UK, ETH Zurich, and a group at Fudan University Shanghai. She also visits Colombi at the Institute of Astrophysics Paris to discuss issues regarding large-structure simulations. The LSC is an international organization. It also has a tight relation with other organizations that focus on gravitational wave observations. The optical group organizes focus sessions at LIGO meetings jointly with other gravitational organizations (VIRGO, AGO etc.) and in independent workshops.Advanced LIGO, the major upgrade of LIGO, is expected to be limited by thermal noise in the most critical ~50-150 Hz frequency band while the performance of several state-of-the art frequency stabilization systems is limited by thermal noise at frequencies as low as a few Hz. This project also studies mechanical properties of crystalline materials (GaAs/AlGaAs, and GaP/AlGaP), a new paradigm for optical coating that has been demonstrated experimentally. Improving dielectric coatings and reducing thermal noise have applications in many high precision optical measurements far beyond LIGO, such as time and frequency measurements, measurements of the equivalence principle, and many others. The computational approach of characterizing amorphous materials will also be useful to many other areas such as nano-scale science, materials science, and bio-science.

该研究项目是一个面向计算的理论努力，旨在了解原子水平的光涂料材料中热噪声的物理起源，并为复合非定形氧化物（Silica，Titania，Titania，Tantala，Hafnia等）中金属元素的最佳比率提供指导。由有限温度下的原子运动引起的热噪声会影响超高分辨率干涉仪的性能，例如激光干涉仪重力波动台（LIGO）中使用的激光干涉仪，并且对LIGO Scientific Collocatory（LSC）具有特别感兴趣。该项目将为计算物理学的研究生提供严格的培训。 PI与许多国际实验和计算材料物理小组进行了合作，包括格拉斯哥英国的一个小组，苏黎世Eth Eth和Fudan University Shanghai的集团。她还访问了巴黎天体物理学研究所的哥伦比，讨论有关大结构模拟的问题。 LSC是一个国际组织。它还与其他关注重力波观察的组织有着密切的关系。光学小组在LIGO会议上与其他引力组织（处女座，AGO等）共同组织集中会议。该项目还研究了晶体材料（GAAS/ALGAA和GAP/ALGAP）的机械性能，这是一种新的光涂层范式，已在实验中证明。改进的介电涂层和减少热噪声的应用在许多高精度的光学测量范围远远超出了Ligo之外，例如时间和频率测量，等效原理的测量值以及许多其他。表征无定形材料的计算方法也将对许多其他领域（例如纳米级科学，材料科学和生物科学）进行有用。