Nano-spectroscopic imaging and control of coupled dynamics in local molecular environments

在化学系化学测量和成像项目的支持下，博尔德科罗拉多大学的Raschke教授计划开发一系列近距离（“近场”）光谱和成像技术，以研究分子的行为以及它们如何与环境相互作用。他和他的团队使用创造性方法的组合来以高分辨率（即纳米空间分辨率）测量快速事件（即飞秒时间尺度）。实验结果提供了关于分子不同量子态的信息，这将有助于在最基本的水平上理解分子的性质和功能。这些知识最终将有助于理解并制造新材料，如催化剂，电子产品和其他光子材料。这个跨学科的项目为Raschke教授实验室的研究生和本科生提供了广泛的研究培训。 他们还将有机会参加社区外联活动，并体验向工业界转让技术的过程。 为了获得光谱进入纳米到分子的长度尺度和它们的动力学，一种新的近场光学扫描探针显微镜模式的组合被开发和应用。在使用飞秒四波混频和光电流光谱的非线性和超快纳米成像中，使用飞秒绝热纳米聚焦，在量子点、量子等离子体激元和强耦合等离子体激元-激子系统中研究了耦合的电子和振动量子动力学。在变温单分子纳米拉曼光谱中，利用纳米机械探针-样品探测和隧穿输运条件，研究了多环芳烃和自组装单分子膜中的光谱扩散、分子内振动能量重新分布、取向动力学和等离子体激元热电子过程。这项研究正在推进基础科学，同时作为技术使能同时提供对分子材料的理解，因为化学纳米成像是使能技术的改进。由于其跨学科的性质，该项目为研究生和本科生提供了广泛的研究培训，包括他们参与社区推广和技术转让到行业。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Raschke of the University of Colorado, Boulder, plans to develop a series of close-up ("near field") spectroscopic and imaging techniques to study the behavior of molecules and how they interact with their environment. He and his group use a combination of creative approaches to measure fast events (i.e. at the femtosecond time scale) at high resolution (i.e. with nanometer spatial resolution). The experiment outcomes provide information about different quantum states of a molecule, which will help to understand a molecule's properties and function at the most elemental level. The knowledge will eventually help to understand and then make new materials as catalysts, electronics, and other photonic materials. This interdisciplinary project provides broad research training for graduate and undergraduate students in Professor Raschke's lab. They will also have the opportunity to participate in community outreach and experience technology transfer to industry. In order to gain the spectroscopic access into the nano- to molecular length scales and their dynamics, a combination of novel near-field optical scanning probe microscopy modalities is developed and applied. In nonlinear and ultrafast nano-imaging using femtosecond four-wave mixing and photo-current spectroscopy the coupled electronic and vibrational quantum dynamics is studied in quantum dots, quantum plasmonic, and strongly coupled plasmon-exciton systems, using femtosecond adiabatic nano-focusing. In variable temperature single molecule nano-Raman spectroscopy, with nano-mechanical tip-sample probing, and tunneling transport conditions, in polyaromatic hydrocarbons and self-assembled monolayer, spectra diffusion, intramolecular vibrational energy redistribution, orientational dynamics, and plasmon hot-electron processes are investigated. This research is advancing basic science while being technology enabling simultaneously providing for the understanding of molecular materials as chemical nano-imaging as the enabling technique is refined. With its interdisciplinary nature this project provides for broad research training for graduate and undergraduate students including their participation in community outreach and technology transfer to industry.