OP: Model Theory of Single Nanoparticle Photothermal Absorption Spectroscopy via Optical Microresonators

华盛顿大学的David J.Masiello获得了化学系化学理论、模型和计算方法项目的支持，以开发理论和实验方法来理解和解释一类新的单粒子光热吸收光谱实验。光热光谱为测量单分子在室温下的吸收光谱提供了一个独特的平台，在生物、材料科学等领域具有潜在的应用前景。马西洛和他的由本科生、研究生和博士后助理组成的不同团队正在努力了解单个纳米级物体，如单分子、量子点和等离子体纳米粒子是如何处理光的。光可以被微粒吸收，也可以被散射。虽然很难测量，但吸收包含有关纳米粒子的重要信息，这些信息在散射中不存在。马西洛的理论进步应用于这些新的最先进的吸收实验，使实验者能够在单个粒子水平上区分吸收和散射。他们还确定了其他令人着迷的现象所需的条件，如实验中使用的高质量微谐振腔中遥远的纳米物体之间的远程、非辐射能量转移和室温量子纠缠。Masiello和他的一位同事开发并教授了一门研究生水平的科学写作课程，旨在为不同的学生群体发展和提高科学交流技能。这项工作的技术重点是：1)开发简单但严格的分析模型，研究分子、量子点和金属纳米结构中的个人和集体电子激发以及它们与其支持的环形微谐振腔的高质量光学耳语走廊模的相互作用；2)将这些模型与Maxwell方程的全波数值模拟结合使用，以了解光热吸收光谱中存在的复杂线型；3)研究光学微谐振器在远距离杂化甚至纠缠在类里德堡等离子体中的纳米物体之间的相互作用和相干能量传递的能力。

David J. Masiello of the University of Washington is supported by an award from the Chemical Theory, Models and Computational Methods Program in the Division of Chemistry to develop theoretical and experimental approaches to understand and interpret a new class of single particle photothermal absorption spectroscopy experiments. Photothermal spectroscopy offers a unique platform to measure absorption spectra of single molecules at room temperature and has many potential applications in biology, materials science and other fields. Masiello and his diverse team of undergraduates, graduate students and postdoctoral associates are working to understand how individual nanoscale objects such as single molecules, quantum dots, and plasmonic nanoparticles process light. The light may be absorbed into the particle or it may be scattered. While it is difficult to measure, absorption contains important information about the nano-particle that is not present in the scattering. Masiello's theoretical advances, applied to these new state-of-the-art absorption experiments, allow the experimentalists to distinguish absorption from scattering at the single particle level. They also determine the conditions that are required for other fascinating phenomena such as long-range, nonradiative energy transfer and room-temperature quantum entanglement between distant nanoscale objects in the high quality microresonator cavities that are used in the experiments. Masiello and a colleague have developed and teach a graduate level course on scientific writing aimed at developing and enhancing the scientific communication skills for a diverse group of students.The technical focus of this work is to: 1) develop simple yet rigorous analytical models of the individual and collective electronic excitations in molecules, quantum dots, and metallic nanostructures as well as their interaction with the high-quality optical whispering-gallery modes of their supporting toroidal microresonator cavity; 2) use these models together with full-wave numerical simulations of Maxwell's equations to understand the complex line shapes present in photothermal absorption spectra; and 3) investigate the ability of optical microresonators to assist in the interaction and coherent energy transfer between distant nanoscale objects hybridized or even entangled in ultra-long-range Rydberg-like plasmons.