Collaborative Research: Stanford-Florida program in Support of LIGO on Coatings and Core Optics

合作研究：斯坦福大学-佛罗里达州支持 LIGO 涂层和核心光学器件的项目

• 批准号: 1707964
• 负责人: Hai-Ping Cheng
• 金额: $ 24万
• 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: 2017
• 资助国家: 美国
• 起止时间: 2017-12-01 至 2021-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1707964&HistoricalAwards=false
• 关键词: Collaborative; Research; Stanford; Florida; program

The detections of gravitational waves from coalescing black holes by the Advanced LIGO detectors has launched the field of gravitational wave astronomy. Increasing the sensitivity of the LIGO detector several times would increase the number of gravitational waves and the types of events observed. Future detectors, such as the A+ LIGO detector, planned for 2021, will be limited by thermal noise associated with the mirror coatings used in the detector optics. The proposed work is a collaborative effort between Martin Fejer's group at Stanford University and Hai-Ping Cheng's group at the University of Florida to develop mirror coatings with lower thermal noise to address this problem for A+ LIGO and beyond. The Stanford gravitational wave research program has been involved for more than two decades in research to enable gravitational wave detectors by working closely with the LIGO Science Collaboration (LSC) to do critical research and mitigate difficult challenges. In the past, Stanford has contributed broadly to the development of novel interferometer components and design, detailed studies of the optics and mitigating optical and thermal noise, and the advanced seismic isolation systems used in Advanced LIGO (aLIGO). Hai-Ping Cheng's group at Florida is involved in computational materials simulations. In support of LIGO, she has modeled atomic structure of amorphous films and evaluated mechanical losses associated with those structures as part of a broader LSC effort to develop low-thermal-noise mirror coatings. While Advanced LIGO has now operated with adequate sensitivity to detect black hole coalescences, its mid-band sensitivity will be limited by thermal noise resulting from mechanical dissipation in the mirror coatings. Stanford has had a leading role within the LSC in developing experimental methods to characterize the optical, elastic, and structural properties of the amorphous materials composing multilayer dielectric mirrors. Florida carries out the current computational materials modeling effort within LSC. The proposed program is a synergistic teaming to combine these skill sets to address a critical issue to meet the design goals of A+ LIGO, developing mirrors with 2-4 times less mechanical loss than the best currently available. The mechanical losses in amorphous materials depend on subtle, preparation-dependent features in their atomic structure. Data on these structural features obtained via the electron diffraction and X-ray scattering methods proposed here is challenging to interpret, as are molecular dynamics predictions of the structure. Methods exist to use the modeling to help interpret the data and the data to help constrain the modeling, which led to the teaming arrangement proposed here. The structural data and predictions for dependence of elastic losses on material composition and process conditions, will become a major contributor to the broader LSC program to develop mirrors for A+ LIGO, guiding the others working on this problem through the thicket of possible synthesis and characterization experiments. Another long-standing effort at Stanford has been in the optical characterization of low-optical loss materials at the sub-ppm/cm level, dating back to the selection between silica and sapphire for initial LIGO test masses. The group has recently begun using the interferometric tool developed for those studies to characterize cryogenic losses in single-crystal silicon samples to evaluate their suitability as test masses in the planned cryogenic LIGO Voyager.

Advanced LIGO 探测器对聚结黑洞的引力波的探测开创了引力波天文学领域。数倍提高 LIGO 探测器的灵敏度将会增加引力波的数量和观测到的事件类型。未来的探测器，例如计划于 2021 年推出的 A+ LIGO 探测器，将受到与探测器光学器件中使用的镜面涂层相关的热噪声的限制。这项拟议的工作是斯坦福大学 Martin Fejer 团队和佛罗里达大学 Hai-Ping Cheng 团队的合作成果，旨在开发热噪声更低的镜面涂层，以解决 A+ LIGO 及其他领域的这一问题。斯坦福大学引力波研究计划二十多年来一直致力于通过与 LIGO 科学合作组织 (LSC) 密切合作来实现引力波探测器的研究，以开展关键研究并应对困难的挑战。过去，斯坦福大学在新型干涉仪组件和设计的开发、光学的详细研究以及减轻光学和热噪声以及高级 LIGO (aLIGO) 中使用的先进隔震系统方面做出了广泛的贡献。佛罗里达州海平程 (Hai-Ping Cheng) 的团队致力于计算材料模拟。为了支持 LIGO，她对非晶薄膜的原子结构进行了建模，并评估了与这些结构相关的机械损失，作为开发低热噪声反射镜涂层的更广泛的 LSC 工作的一部分。虽然先进的 LIGO 现在已经具有足够的灵敏度来检测黑洞聚结，但其中频灵敏度将受到镜面涂层中机械耗散产生的热噪声的限制。斯坦福大学在 LSC 中发挥主导作用，开发实验方法来表征构成多层介质镜的非晶材料的光学、弹性和结构特性。佛罗里达州在 LSC 内开展当前的计算材料建模工作。拟议的计划是一个协同团队，将这些技能组合起来，解决一个关键问题，以满足 A+ LIGO 的设计目标，开发出机械损失比目前最好的镜子低 2-4 倍的镜子。非晶材料的机械损失取决于其原子结构中微妙的、与制备相关的特征。通过此处提出的电子衍射和 X 射线散射方法获得的这些结构特征的数据难以解释，结构的分子动力学预测也是如此。存在使用建模来帮助解释数据以及使用数据来帮助约束建模的方法，这导致了此处提出的分组安排。弹性损失对材料成分和工艺条件的依赖关系的结构数据和预测，将成为更广泛的 LSC 计划的主要贡献者，为 A+ LIGO 开发镜子，指导其他人通过可能的合成和表征实验来解决这个问题。斯坦福大学的另一项长期工作是对亚 ppm/cm 级别的低光损耗材料进行光学表征，这可以追溯到最初 LIGO 测试质量中二氧化硅和蓝宝石的选择。该小组最近开始使用为这些研究开发的干涉测量工具来表征单晶硅样品的低温损失，以评估它们作为计划的低温 LIGO Voyager 中的测试质量的适用性。

项目成果

Hidden structure in the medium-range order of amorphous zirconia-tantala films

非晶氧化锆-钽薄膜的中程隐藏结构

• DOI: 10.1103/physrevb.108.054103
• 发表时间: 2023
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Mishkin, Alec;Jiang, Jun;Zhang, Rui;Cheng, Hai-Ping;Prasai, Kiran;Bassiri, Riccardo;Fejer, Martin
• 通讯作者: Fejer, Martin

Amorphous Zirconia-doped Tantala modeling and simulations using explicit multi-element spectral neighbor analysis machine learning potentials (EME-SNAP)

使用显式多元素光谱邻域分析机器学习潜力 (EME-SNAP) 对非晶氧化锆掺杂 Tantala 进行建模和模拟

• DOI: 10.1103/physrevmaterials.7.045602
• 发表时间: 2023
• 期刊: Physical Review Materials
• 影响因子: 3.4
• 作者: Jiang, Jun;Li, Xiang-Guo;Mishkin, Alec S.;Zhang, Rui;Bassiri, Riccardo;Fry, James N.;Fejer, Martin M.;Cheng, Hai-Ping
• 通讯作者: Cheng, Hai-Ping

High Precision Detection of Change in Intermediate Range Order of Amorphous Zirconia-Doped Tantala Thin Films Due to Annealing

高精度检测非晶氧化锆掺杂钽薄膜因退火引起的中程序变化

• DOI: 10.1103/physrevlett.123.045501
• 发表时间: 2019
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Prasai, K.;Jiang, J.;Mishkin, A.;Shyam, B.;Angelova, S.;Birney, R.;Drabold, D. A.;Fazio, M.;Gustafson, E. K.;Harry, G.
• 通讯作者: Harry, G.

Annealing‐Induced Changes in the Atomic Structure of Amorphous Silica, Germania, and Tantala Using Accelerated Molecular Dynamics

退火——利用加速分子动力学引起无定形二氧化硅、二氧化锗和钽原子结构的变化

• DOI: 10.1002/pssb.202000519
• 发表时间: 2021
• 期刊: physica status solidi (b
• 作者: Prasai, Kiran;Bassiri, Riccardo;Cheng, Hai-Ping;Fejer, Martin M.
• 通讯作者: Fejer, Martin M.

Analysis of two-level systems and mechanical loss in amorphous ZrO 2 -doped Ta 2 O 5 by non-cage-breaking and cage-breaking transitions

非晶ZrO 2 掺杂Ta 2 O 5 中非破笼和破笼转变的两能级系统和机械损失分析

• DOI: 10.1063/5.0046332
• 发表时间: 2021
• 期刊: The Journal of Chemical Physics
• 作者: Jiang, Jun;Mishkin, Alec S.;Prasai, Kiran;Zhang, Rui;Yazback, Maher;Bassiri, Riccardo;Fejer, Martin M.;Cheng, Hai-Ping
• 通讯作者: Cheng, Hai-Ping