报告题目 | Study of nonadiabatic dynamics and conical intersections by nonlinear broadband X -ray spectroscopy |
报告人 | Prof. Shaul Mukamel |
报告人单位 | 加州大学Irvine分校化学系 |
报告时间 | 2017-12-07 |
报告地点 | 合肥微尺度物质科学国家实验室一楼科技展厅 |
主办单位 | 合肥微尺度物质科学国家实验室 |
报告介绍 | 报告摘要:
A wide range of time-resolved spectroscopic techniques which span the infrared to the X-ray regimes and can be used for probing the nonadiabatic dynamics in the vicinity of conical intersections, transient electronic and vibrational probes and their theoretical signal calculations are surveyed.
Multidimensional spectroscopy uses sequences of optical pulses to study dynamical processes in complex molecules through correlation plots involving several time delay periods. We demonstrate how stimulated Raman detection of an X-ray probe may be used to monitor the phase and dynamics of the nonequilibrium valence electronic state wavepacket created by e.g. photoexcitation, photoionization and Auger processes. Conical intersections (CoIn) dominate the pathways and outcomes of virtually all photophysical and photochemical molecular processes. Despite extensive experimental and theoretical effort CoIns have not been directly observed yet and the experimental evidence is being inferred from fast reaction rates and some vibrational signatures. Novel ultrafast X ray probes for these processes will be presented. Short X-ray pulses can directly detect the passage through a CoIn with the adequate temporal and spectral sensitivity. The technique is based on a coherent Raman process that employs a composite femtosecond/attosecond X-ray pulse to directly detect the electronic coherences (rather than populations) that are generated as the system passes through the CoIn. Streaking of time-resolved photoelectron spectroscopy (TRPES) signals offers another powerful window into the joint electronic/vibrational dynamics at conical intersections.
报告人简介:
Shaul Mukamel教授是多维相干光谱领域最杰出的理论科学家之一。他于1976年在以色列Tel-Aviv大学获得博士学位,随后于美国MIT,Rice大学进行研究工作。他现任美国加州大学Irvine分校教授,美国国家科学院院士。Mukamel教授致力于多维光谱理论、光子材料多体理论、蛋白质折叠、电子转移、x-射线光谱、非线性光谱理论等方面的研究,是国际上光谱理论等领域的知名专家。已在JACS、PRL、PNAS等杂志上发表论文900余篇。所著的“Principles of Nonlinear Optical Spectroscopy”一书被称为非线性光谱学的“红宝书”。 |