Tailoring Light-Matter Interaction in Plasmonic Nanostructures based on Epitaxial Metallic Films: From Classical to Quantum Regime

技术描述：等离子体领域是光子学中一个充满活力的前沿领域，它旨在通过利用金属或重掺杂半导体中的等离子体共振来控制远低于衍射极限的光-物质相互作用。与几乎所有等离子体应用相关的一个突出挑战是由于晶界和表面粗糙度引起的吸收或散射所带来的高损耗。在常用的材料中，银（Ag）在宽波长范围内具有最好的特性和最低的损耗。该项目的目标是研究原子光滑外延银薄膜，以及由这种薄膜制造或放置在它们附近的纳米结构，作为等离子体应用的新平台。具体目标包括：(i)表征光学常数和测量表面等离子激元极化子在外延银薄膜中的传播距离。通过最小化晶界和表面粗糙度的散射，将研究诸如电子-电子和电子-声子散射等内在过程如何决定金属薄膜的光学特性。（ii）杂化纳米结构中激子-等离子体相互作用的研究，特别是外延薄膜和由外延薄膜制成的等离子体纳米结构附近的单个半导体发射体的量子动力学。非技术描述：本研究项目是在经典和量子体制下原子光滑外延银膜上的光-物质相互作用。这项研究意义重大，因为外延金属薄膜在基础科学和应用方面提供了许多令人兴奋的机会。提高对如何使用最高质量的金属薄膜形成光物质相互作用的理解可能会导致新的光电器件的发现。该项目为研究生和本科生提供了广泛的培训机会。此外，PI计划实施“翻转课堂”，以提高大型物理入门课程的教学效率，并与德克萨斯大学埃尔帕索分校（University of Texas at El Paso）合作建立一个桥梁项目，招募和指导少数民族学生。

Technical Description: The field of plasmonics is a vibrant frontier in photonics which aims at manipulating light-matter interaction well below the diffraction limit by utilizing plasmonic resonances in metals or heavily doped semiconductors. One outstanding challenge relevant to practically all plasmonic applications is the high loss introduced by either absorption or scattering due to grain boundaries and surfaces roughness. Among the commonly used materials, silver (Ag) has the best characteristics and the lowest loss in a wide wavelength range. The objective of this project is to investigate atomically-smooth epitaxial Ag films, as well as nanostructures either fabricated from such films or placed in their close proximity, as a new platform for plasmonic applications. The specific aims include: (i) Characterization of optical constants and measurement of surface plasmon polariton propagation distances in epitaxial Ag films. By minimizing scattering from grain boundaries and surface roughness, how intrinsic processes such as electron-electron and electron-phonon scattering determine the optical properties of metallic films will be examined. (ii) Investigation of exciton-plasmon interaction in hybrid nanostructures, and particularly the quantum dynamics of individual semiconductor emitters near the epitaxial thin films and plasmonic nanostructures fabricated from such films.Non-technical Description: This research project is on light-matter interactions at atomically-smooth epitaxial silver films in both the classical and quantum regimes. The research is significant because epitaxial metal films provide many exciting opportunities in fundamental science and applications. Improved understanding of how to shape light-matter interaction using the highest quality metallic films may lead to discoveries of new optoelectronic devices. The project provides extensive training opportunities for graduate and undergraduate student. In addition, the PI plans to implement "flipped classroom" for improving instructional effectiveness in large introductory physics courses, and also to establish a bridge program in collaboration with the University of Texas at El Paso to recruit and mentor minority students.