Large Scale Nanopolaritonics

加州大学洛杉矶分校的丹尼尔诺伊豪泽获得了化学理论、模型和计算方法项目的奖项，以表彰他开发了一种理论方法来探索大量分子的分子纳米极化。分子纳米极化作用学旨在统一纳米尺度上的辐射和物质的处理。 关于这一主题的先前奖项已经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，并预测分子将具有大的设计响应，其可以随意操纵等离子体携带结构中的辐射传输。 目前的研究通过发展理论在更大范围内统一了分子和电磁治疗，这些理论通过明确的时间依赖性治疗来处理大量分子，并研究分子和电磁等离子体的相互作用和影响。 该提案解决了将分子直接嵌入等离子体携带结构顶部的难题，需要开发多尺度方法，该方法在内部区域采用详细的时间依赖性轨道或密度矩阵处理，并辅之以外部尺度上的无轨道或麦克斯韦研究。 该方法使用了一个时间依赖的模拟复杂的泊松描述，从而显着增加了FDTD的时间步长，使其相称的电子动力学。 此外，新的嵌入技术允许设计的无轨道描述的等离子体结构与正确的频率响应，从而允许大规模的嵌入。 金属结构支持传播等离子体激元，分子，无论是几个单独的或大的集群，通过偶极诱导场相互作用。 Nanopolaritonics是该领域的一个新名称，旨在统一治疗。 一个众所周知的方向是由于与金属等离子体产生的强场的相互作用对分子的影响（其可以在特定几何形状中放大几个数量级，特别是涉及角落）。 然而，纳米激元学还包括同样重要且很少探索的其他方向，即分子影响等离子体波的传播。 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，他们开发的嵌入方法，吸附的分子被描述量子力学以及底层的吸附结构。更大的区域用更近似的方法来描述，如无轨道方法或麦克斯韦处理，修改后集中在小尺度上。 该方法的应用将是大量的：等离子体传输的门控，个别分子的传感，并通过它们对等离子体的影响，非线性现象及其对局部辐射转移和吸收的影响吸附分子。 最重要的特点是，这项研究统一了辐射和电子动力学这两个不同的领域，与现实的治疗，可以表现出新的物理特征超越微扰或模型型治疗。

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.