Interaction of electromagnetic pulses and nanostructures

该奖项支持旨在开发和应用新方法来模拟电磁波和物质相互作用的计算研究。几乎我们日常生活中的一切，从光合作用到电视屏幕和移动电话，都是电磁场（光）和物质某种形式相互作用的结果。物质中的原子和分子可以吸收和发射光，并在电磁场的作用下相互作用。当电磁场较弱时，它们的相互作用改变了电子和原子核的动力学，但电磁场本身保持不受干扰。然而，当强电磁场与物质相互作用时，除了入射场外，电子和原子核的运动还会产生电磁场。诱导场可以大大大于入射场，这可以显著改变材料的性质。这个项目的目标是模拟耦合光-物质系统的相互作用，通过使用物质的量子描述和经典场的方法来达到自洽的耦合形式的电磁场。所开发的方法将广泛应用于具有基础和技术重要性的纳米材料。该奖项还将为研究生、本科生和高中生提供广泛的跨学科研究培训机会，包括物理学、电气工程、材料科学、量子力学模拟、高性能计算和新型计算算法。此外，PI将通过范德比尔特教师研究经验项目接待高中教师，并与他们一起开发纳米科学和计算建模等新兴科学和技术前沿的课堂模块。该奖项支持旨在开发和应用与时间相关的无轨道（TD-OF）方法与麦克斯韦方程相结合的计算研究，以描述电磁波和物质的相互作用。耦合麦克斯韦TD-OF方程在微观框架下平等地处理电子和光子动力学。在耦合框架中，在存在时变矢量势的情况下，使用量子力学方法计算密度和电流，然后使用量子力学计算的时变微观电流和密度求解麦克斯韦方程组。一种新的方法，黎曼-希尔伯斯坦形式论，将被用于通过“光子的波函数”的传播来求解麦克斯韦方程组。OF方法将允许对具有电子量子描述的实验相关尺寸的系统进行电动力学模拟。模拟的结果将与最近的实验结果进行检验。间隙等离子体（电荷转移等离子体，等离子体隧道结，高谐波产生）和二维等离子体（实空间映射，边缘等离子体，太赫兹等离子体）的计算挑战将继续进行。该奖项还将为研究生、本科生和高中生提供广泛的跨学科研究培训机会，包括物理学、电气工程、材料科学、量子力学模拟、高性能计算和新型计算算法。此外，PI将通过范德比尔特教师研究经验项目接待高中教师，并与他们一起开发纳米科学和计算建模等新兴科学和技术前沿的课堂模块。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NONTECHNICAL SUMMARYThis award supports computational research aimed at developing and applying new methods to model the interaction of electromagnetic waves and matter. Almost everything in everyday life around us, from photosynthesis to television screens and mobile phones, is a result of some form of interaction of electromagnetic fields (light) and matter. Atoms and molecules in matter can absorb and emit light and can interact with each other coupled to electromagnetic fields. When electromagnetic fields are weak, their interaction changes the dynamics of electrons and nuclei, but the electromagnetic fields themselves remain unperturbed. When strong electromagnetic fields interact with matter, however, the motion of the electrons and the nuclei induce electromagnetic fields in addition to the incident fields. The induced fields can be substantially larger than the incident field and this can significantly change the material properties. The goal of this project is to simulate the interaction of coupled light-matter systems by using a quantum description of the matter and classical field approach to the electromagnetic fields in a self-consistent, coupled formalism. The developed methods will be applied to a wide range of nanomaterials that are of fundamental and technological importance. This award will also provide broad research training opportunities for graduate, undergraduate, and high school students in an interdisciplinary environment overarching physics, electrical engineering, materials science, quantum mechanical simulations, high-performance computing, and novel computational algorithms. In addition, the PI will host high-school teachers through the Vanderbilt Research Experiences for Teachers program, and develop classroom modules with them on emerging scientific and technological frontiers in nanoscience and computational modeling.TECHNICAL SUMMARYThis award supports computational research aimed at developing and applying a time-dependent orbital-free (TD-OF) approach coupled with Maxwell equations to describe the interaction of electromagnetic waves and matter. The coupled Maxwell TD-OF equations treat the electron and photon dynamics in a microscopic framework on equal footing. In the coupled frame, the densities and currents are calculated using a quantum mechanical approach in the presence of a time-dependent vector potential, and then Maxwell equations are solved using the quantum mechanically calculated time-dependent microscopic currents and densities. A new approach, the Riemann-Silberstein formalism, will be used to solve Maxwell equations by the propagation of "the wave function of the photon". The OF approach will allow for electrodynamic simulations to be performed for systems of experimentally relevant sizes with a quantum description of the electrons. The results of the simulations will be tested against recent experimental results. Computational challenges of gap plasmonics (charge transfer plasmons, plasmonic tunnel junctions, high harmonic generation) and 2D plasmonics (real space mapping, edge plasmons, terahertz plasmonics) will be pursued. This award will also provide broad research training opportunities for graduate, undergraduate, and high school students in an interdisciplinary environment overarching physics, electrical engineering, materials science, quantum mechanical simulations, high-performance computing, and novel computational algorithms. In addition, the PI will host high-school teachers through the Vanderbilt Research Experiences for Teachers program, and develop classroom modules with them on emerging scientific and technological frontiers in nanoscience and computational modeling.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.