研究・研究者
研究会・セミナー
| 演 題 | 「Using Wave-Packet Interferometry to Monitor the External Vibrational Control of Electronic Excitation Transfer」 |
|---|---|
| 日 時 | 2008年09月02日(火) 15:00 より 17:00 まで |
| 講演者 | Prof. Jeffrey A. Cina （Department of Chemistry, University of Oregon Full member, Oregon Center for Optics） |
| 場 所 | 分子科学研究所 研究棟201セミナー室 |
| 概 要 | I will describe our investigations on the control of electronic energy transfer in molecular dimers through the preparation of specific vibrational coherences prior to electronic excitation. Laser-driven coherent nuclear motion can affect the instantaneous resonance between site-excited electronic states so as to influence short-time electronic excitation transfer (EET). We have proposed nonlinear wave-packet interferometry (nl-WPI) experiments to monitor the electronic and vibrational dynamics in dimer complexes following initial vibrational excitation. The electronic transition moments of the constituent monomers are assumed to have a fixed relative orientation, while the overall orientation of the complex is distributed isotropically. In nl-WPI measurements, two pairs of polarized, phase-related femtosecond pulses generate superpositions of coherent nuclear wave packets in optically accessible electronic states. Interference in the fluorescence signal due to the overlap among the superposed wave packets provides amplitude-level information on the nuclear and electronic dynamics. I will present expressions for the nl-WPI signal following the control pulse (or control-pulse sequence), including the limiting case of coincident arrival by pulses within each phase-related pair in which nl-WPI reduces to a conventional fluorescence-detected pump-probe experiment. I will show the results of model calculations with Hamiltonian parameters chosen to represent dithia-anthracenophane, an energy-transfer complex that has been studied by Yamazaki and co-workers using time-resolved polarized fluorescence. Connections will be made throughout with WPI experiments on small molecules in the gas phase and in condensed media, including recent supersonic jet measurements on I2 by the Ohmori lab. |
| お問合せ先 | 大森賢治 |
