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，科罗拉多大学博尔德分校的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。他和他的团队使用了一系列创造性的方法，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和制造催化剂、电子和其他光子材料等新材料。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训练。他们还将有机会参与社区外展活动，并体验技术向工业的转移。为了获得纳米到分子长度尺度及其动力学的光谱通道，一种新型的近场光学扫描探针显微技术被开发和应用。利用飞秒绝热纳米聚焦技术，研究了量子点、量子等离子体和强耦合等离子体激子系统的非线性和超快纳米成像中电子和振动量子动力学。在变温度单分子纳米拉曼光谱中，采用纳米机械探针探针和隧道输运条件，研究了多芳烃和自组装单层中的光谱扩散、分子内振动能量重分配、取向动力学和等离子体热电子过程。这项研究正在推动基础科学的发展，同时也为分子材料的理解提供了技术支持，因为化学纳米成像技术正在完善。该项目具有跨学科的性质，为研究生和本科生提供广泛的研究培训，包括参与社区外展和向行业转移技术。

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.