Large Scale Nanopolaritonics

大规模纳米极化

• 批准号: 1112500
• 负责人: Daniel Neuhauser
• 金额: $ 43.5万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1112500&HistoricalAwards=false
• 关键词: Large; Scale; Nanopolaritonics

Daniel Neuhauser of UCLA is supported by an award from the Chemical Theory, Models and Computational Methods program for work to develop a theoretical methodology to explore molecular nanopolaritonics with a large number of molecules. Molecular Nanopolaritonics intends to unify the treatment of radiation and matter on the nano scale. A previous award on this subject has introduced the concept of a unified treatment of matter and radiation on the nanoscale with arbitrary geometries and predicted that molecules will have large designed responses which can manipulate at will the transport of radiation in plasmon carrying structures. The present research unifies molecular and electromagnetic treatments on a larger scale through the development of theories that handle multitude of molecules with explicit time-dependent treatments and study the interaction with, and effects of, molecules and electromagnetic plasmons. The proposal tackles the difficult problem of embedding molecules directly on top of plasmon carrying structures, necessitating the development of multi-scale approaches that employ a detailed time-dependent orbital or density-matrix treatments in an inner region, supplemented by orbital-free or Maxwell studies on outer scales. The approaches use a time-dependent analogue of complex-Poisson descriptions, thereby significantly increasing the time-step of FDTD and making it commensurate with that of electronic dynamics. Further, new embedding techniques allow for designed orbital-free descriptions of plasmonics structures with the correct frequency response, thereby allowing large-scale embedding.There are two disparate phenomena associated with radiation on the small scale. Metal structures support propagating plasmons, and molecules, whether few separate ones or large clusters, interact by dipole-induced fields. Nanopolaritonics is a recent name for the field which aims to unify the treatment. A well known direction is the effect on the molecules due to the interaction with the strong fields generated by the metal plasmons (which can be magnified by orders of magnitude in specific geometries, especially involving corners). However, Nanopolaritonics also includes the equally important and little-explored other direction, whereby molecules influence the propagation of plasmon waves. The PI with his group have shown in simulations that the effects are strong in both directions. At present they develop embedding approaches whereby adsorbed molecules are described quantum mechanically as well as the underlying adsorbing structure. Bigger regions are described by more approximate methods, such as orbital-free methods or Maxwell treatments, modified to concentrate on small scales. Applications of the methodology will be plenty: gating of plasmonics transport, sensing of individual molecules individually and through their effects on plasmons, non-linear phenomena and their effects on localized radiation transfer and absorption by adsorbed molecules. The most important feature is that this research unifies the two disparate fields of radiation and electronic dynamics, which taken together with realistic treatments, can exhibit novel physical features beyond perturbative or model-type treatments.

加州大学洛杉矶分校的Daniel Neuhauser得到了化学理论、模型和计算方法计划颁发的奖项的支持，因为他致力于开发一种理论方法来探索具有大量分子的分子纳米极化子。分子纳米极化学旨在将辐射和物质的处理统一在纳米尺度上。此前关于这一主题的一个奖项引入了在具有任意几何形状的纳米尺度上统一处理物质和辐射的概念，并预测分子将具有巨大的设计响应，可以随意操纵辐射在等离子体携带结构中的传输。目前的研究通过发展理论，以显式的时间相关处理来处理大量分子，并研究与分子和电磁等离子体的相互作用和影响，在更大范围内将分子和电磁治疗统一起来。该提议解决了将分子直接嵌入到等离子体携带结构顶部的难题，需要开发多尺度方法，在内部区域采用详细的依赖时间的轨道或密度矩阵处理，并辅之以外部尺度的无轨道或麦克斯韦研究。该方法使用复泊松描述的时间相关模拟，从而显著增加了FDTD的时间步长，并使其与电子动力学的时间步长相称。此外，新的嵌入技术允许设计具有正确频率响应的无轨道等离子体结构描述，从而允许大规模嵌入。在小尺度上存在两种与辐射相关的不同现象。金属结构支持传播的等离子激元，分子，无论是几个独立的或大的团簇，都通过偶极感应场相互作用。纳米极化电子技术是该领域的一个新名称，旨在统一治疗方法。一个众所周知的方向是，由于与金属等离子体产生的强场相互作用而对分子产生的影响(在特定的几何形状，特别是涉及角落的情况下，可以放大几个数量级)。然而，纳米极电子也包括同样重要但很少被探索的其他方向，分子通过这些方向影响等离子激元波的传播。PI和他的团队在模拟中表明，这种影响在两个方向上都很强。目前，他们开发了嵌入方法，通过这种方法，吸附的分子以及潜在的吸附结构被量子力学描述。更大的区域被更接近的方法描述，例如无轨道方法或麦克斯韦处理，修改后集中在小尺度上。这一方法论的应用将是广泛的：等离子体输运的门控，单个分子及其对等离子体的影响的传感，非线性现象及其对被吸附分子局域辐射传输和吸收的影响。最重要的特点是，这项研究将辐射和电子动力学这两个不同的领域结合在一起，结合现实的治疗方法，可以展示出超越微扰或模型类型治疗的新的物理特征。