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: 1068138
• 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: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1068138&HistoricalAwards=false
• 关键词: Understanding; Reducing; Thermal; Noise; via

This award supports a theoretical effort to understand the physical origin of thermal noise in optical coating materials at the atomic level. Thermal noise can affect the performance of ultra high-precision interferometers such as employed in the Laser Interferometer Gravitational- Wave Observatory (LIGO). This research will aim at development of atomistic models for various amorphous coating materials through investigation of the mechanical properties, as well as the effects of doping (i.e. mix-in other oxides) using large-scale computation. The research will be coordinated with the Optics Working Group of the LIGO Scientific Collaboration. The work plan has three major parts: 1) Understanding thermal noise in fused silica, 2) understanding effects of defects, doping, and interfaces in layered films such as tantala-silica, and 3) cyber-designing materials with optimal properties. Thermal noise is the energy released by mechanical interactions inside the coating materials. LIGO experimenters are approaching this problem empirically by measuring these mechanical losses in various coating materials such as silica, titania, tantala, and hafnium. This research would provide the basis for a more systematic approach for coating materials since, currently, very little is known about those microscopic internal processes of glassy materials that lead to mechanical losses. The theoretical studies of these materials in this project will inform future experiments. Improving dielectric coatings and reducing thermal noise has applications in many high precision optical measurements far beyond LIGO. The computational approach of characterizing amorphous materials will also be useful to many other areas such as nano-scale science, material science, and bio-science. The project will provide rigorous training for graduate students and postdoctoral researchers in computational physics.

该奖项支持在原子水平上理解光学涂层材料热噪声物理起源的理论工作。热噪声会影响激光干涉仪引力波天文台 (LIGO) 等超高精度干涉仪的性能。这项研究旨在通过研究机械性能以及大规模使用掺杂（即混合其他氧化物）的影响，开发各种非晶涂层材料的原子模型该研究将与 LIGO 科学合作组织的光学工作组协调进行。该工作计划包括三个主要部分：1）了解熔融石英中的热噪声，2）了解层状薄膜中的缺陷、掺杂和界面的影响。 3) 具有最佳性能的网络设计材料 热噪声是涂层材料内部机械相互作用释放的能量，LIGO 实验人员正在通过测量各种机械损失来凭经验解决这个问题。二氧化硅、二氧化钛、钽和铪等涂层材料这项研究将为涂层材料的更多方法提供基础，因为目前对导致机械损失的玻璃材料的微观内部过程知之甚少。该项目中对这些材料的研究将为未来的实验提供信息，其在许多高精度光学测量中的应用远远超出了 LIGO。表征非晶材料的计算方法也将适用于许多其他领域。该项目将为计算物理领域的研究生和博士后研究人员提供严格的培训。