OP-Molecular Radiative and Relaxation Processes

加州大学欧文分校的Shaul Mukamel获得了化学系化学理论、模型和计算方法项目的奖项。Mukamel和他的同事设计了尖端的光谱实验，并开发了解释结果的模型和方法。理解和控制分子中电子和原子核的运动可以决定化学反应和能量传递过程的速率和结果。其中包括在自然光合作用和人工光收集装置中将太阳能转化为电能。该计划通过测量复杂分子对超快光学激光脉冲序列的响应来开发研究这些基本事件的方法。新开发的激光源使这种实验成为可能。模型和实用的计算工具被开发用于解释和分析这些实验和提取潜在的分子信息。Mukamel教授和他的研究小组与世界各地领先的实验研究小组密切合作。新的实验技术涉及精心定时脉冲序列的设计和广泛应用于分子和分子聚集体，以及在凝聚相。光谱学技术旨在直接探测电子和振动相干性，以及玻恩·奥本海默近似失效的非绝热动力学。设计了宽带共振和非共振拉曼技术，可以直接探测分子通过锥形交叉点的通道，并制定了适当的模拟协议。一个高度直观的，图解的超级算子形式被开发用于计算分子对量子和随机光的响应，并应用于通过利用脉冲整形，相位控制和手性极化配置创建新的光脉冲序列。研究了新的非线性信号，旨在通过电子和核相干提供圆锥相交的明确光谱特征。光的量子特性，如光子纠缠，通过提供经典光无法获得的信息，被用作探测分子和发色团聚集体的额外工具。例如，纠缠和压缩光子提供了其他方法无法实现的时间和光谱分辨率。结合单个纠缠光子的巧合测量和干涉测量的检测方案进行了探索，并用于研究光合天线和反应中心的光收集中的基本电荷和能量迁移过程。对具有时间门控和光谱门控的多光子重合信号进行了预测。计算并展示了光子统计测量和高阶辐射场相关函数，为分子动力学过程提供了新的光谱工具。利用荧光或电流对相干光信号的非相干检测方案进行了开发和研究，该方案具有很高的灵敏度，可以对单个分子进行研究。

Shaul Mukamel, of the University of California, Irvine is supported by an award from the Chemical Theory, Models and Computational Methods program in the Division of Chemistry. Mukamel and his coworkers design cutting-edge spectroscopy experiments and develop models and methods for interpreting the results. Understanding and controlling the motions of electrons and nuclei in molecules can determine the rates and outcomes of chemical reactions and energy transfer processes. These include the conversion of solar energy into electric energy in natural photosynthesis and in artificial light harvesting devices. This program develops methods for studying these elementary events by measuring the response of complex molecules to sequences of ultrafast optical laser pulses. Such experiments are made possible by newly-developed laser sources. Models and practical computational tools are developed for the interpretation and analysis of these experiments and extracting the underlying molecular information. Professor Mukamel and his research group collaborate closely with leading experimental research groups all over the world.Novel experimental techniques involving carefully-timed pulse sequences are designed and broadly applied to molecules and molecular aggregates as well as in the condensed phase. Spectroscopic techniques that aim at the direct detection of electronic and vibrational coherence, as well as nonadiabatic dynamics where the Born Oppenheimer approximation breaks down, are developed. Broadband resonant and off-resonant Raman techniques that can directly probe the passage of molecules through conical intersections are designed, and adequate protocols for their simulation are developed. A highly-intuitive, diagrammatic superoperator formalism is developed for computing the response of molecules to quantum and stochastic light and applied towards creating novel optical pulse sequences by utilizing pulse shaping, phase control, and chiral polarization configurations. New nonlinear signals aimed at providing unambiguous spectroscopic signatures of conical intersections through electronic and nuclear coherences are investigated. The quantum properties of light, such as photon entanglement are used as additional tools for probing molecules and chromophore aggregates by providing information that is not accessible by classical light. For example, entangled and squeezed photons offer temporal and spectral resolutions not achievable by other means. Detection schemes that combine coincidence measurements of individual entangled photons and interferometry are explored and used to investigate the elementary charge and energy migration processes in light harvesting in photosynthetic antennae and reaction centers. Signals involving multiple photon coincidence with temporal and spectral gating are predicted. Photon statistics measurements and higher-order radiation field correlation functions are calculated and shown to provide novel spectroscopic tools for molecular dynamical processes. Incoherent detection schemes of coherent optical signals by fluorescence or electric currents, which are very sensitive and can allow the study of single molecules are developed and investigated.