报告题目: Do we live in a Quantum World? Coherent multidimensional studies of quantum coherence effects in biological systems
报告摘要：The relative importance of quantum coherence effects in biological systems has long been debated. At the molecular level, the discussion reduces to the spatial and temporal coherence of the corresponding wavefunction describing the biological response function. This talk will briefly explore the biological functions of energy transport in photosynthetic systems and photoisomerization processes to provide two different examples of evolutionarly optimization. The focus will be on the photoisomerization process of rhodopsin (Rh) and bacteriorhodopsin (bR). In 2D spectra for Rh and bR, we observe very strong modulation of spectra related to the reactant/product surfaces by the very modes involved in the structural transition. In the case of Rh, the steric repulsive forces of the excited cis conformation state impulsively direct the system to the conical intersection (CI) within a half period of the localized C11-C12 bond, the key torsional motion directing the isomerization. In bR, the trans conformation allows exploration of larger nuclear configuration phase space; yet strong vibrational coherences are still observed. By comparison to multi-configuration quantum chemistry calculations, we assign this unusual nuclear-electronic coupling to principally the bond elongation coordinate periodically mixing the S1 and S2 electronic surfaces. It is this coupling that dynamically directs the photoisomerization in bR. Nature has found 2 solutions to beat rapid intramolecular vibrational redistribution processes for such high vibrational density of states that normally occur within 100 fs time scales. The vibrational coupling to electronic surfaces and imposed direction is dissipation driven. Nature does not try to engineer the protein/bath to conserve coherences but rather exploits dissipation to direct biological processes. This simple concept, mastered by nature over all relevant time and spatial dimensions is truly the marvel of biology.
报告人简介： R. J. Dwayne Miller 教授是加拿大多伦多大学学院教授（University Professor），2010年-2019年任德国马克斯普朗克物质结构与动力学研究所所长（Max Planck Director），在超快光物理和分子物理领域享有盛誉。Miller教授是超快电子衍射技术的开创者之一，曾获得欧洲物理学会激光科学奖，皇家化学会百年纪念奖（Centenary Prize），皇家化学会卢瑟福奖章（Rutherford Medal）,在超快分子动力学领域发表论文300余篇，其中包括Nature和Science正刊10篇
主持 联系人：李铮 (Email: zheng.li@pku.edu.cn)
科学前沿报告会(559)
