Elisa Palacino Gonzalez - Molecular Photodynamics of Open Quantum Systems. Simulation of Nonlinear Optical Spectroscopies using Nonperturbative Approaches
- Datum: 17.10.2018
- Uhrzeit: 10:45 - 11:45
- Vortragende(r): Elisa Palacino Gonzalez
- Theoretical Chemistry, Technical University of Munich, Garching
- Ort: CFEL (Bldg. 99)
- Raum: Seminar Room III, EG.080
- Gastgeber: Angel Rubio
In this talk, I will demonstrate how the nonperturbative approaches can be efficiently applied to two different problems of femtosecond molecular spectroscopy.
In the first part of my talk, I will concentrate on the spectroscopic elucidation of ultrafast electron-transfer processes. To this end, l consider a model of a spectroscopically accessible avoided crossing formed by the lowest two excited singlet states in the vicinity of the Franck-Condon region of a polyatomic molecule, augmented with a higher excited electronic state. The considered system reaction mode is coupled to a harmonic bath, which is responsible for the relaxation dynamics. The electronic interstate-coupling is assumed strong, so that the electron-transfer dynamics deviates from the Fermi-Golden behavior, showing electronic and vibrational beatings. A comprehensive mapping of the nonadiabatic wave packet dynamics in such a system calls for the application of several complementary spectroscopic techniques. I simulate with computational methods the outcome of such a concerted experimental effort and compute the signals of four well-stablished two-pulse spectroscopies: time and frequency resolved fluorescence, transient absorption pump-probe and femtosecond stimulated Raman spectroscopy. The simulations are based on an exact numerical solution of the driven time-dependent multi-state Redfield master equation . The effects of laser pulse shape and pulse overlap are fully included. We demonstrate which features of the photoinduced dynamics, such as electronic/nuclear populations, electronic/nuclear coherences or electronic/nuclear charge transfer processes are imprinted in the simulated signals. It will be shown that a fairly complete and systematic picture of the coupled electronic/nuclear dynamics at avoided crossings can be obtained in this manner.
The second part of my talk deals with the simulation of nonlinear signals beyond the regime of weak system-field coupling. I will focus on the theoretical description, interpretation and information content of double-pump femtosecond single-molecule signals of individual chromophores in the weak-field regime  and in the strong-field regime .
. M.F. Gelin,D. Egorova and W. Domcke, Chem. Phys., 2005, 312, 135-143
. E. Palacino-González, M. F. Gelin and W. Domcke. Theoretical Aspects of Femtosecond Double-Pump Single-Molecule Spectroscopy I. Weak-field regime. Phys. Chem. Chem. Phys., 2017, 19, 32296-32306
. E. Palacino-González, M. F. Gelin and W. Domcke. Theoretical Aspects of Femtosecond Double-Pump Single-Molecule Spectroscopy II. Strong-field regime Phys. Chem. Chem. Phys., 2017, 19, 32307-32319