title: Observation and control of coherent torsional dynamics in a quinquethiophene molecule.
abstract: By applying femtosecond pump-probe spectroscopy to a substituted quinquethiophene molecule in solution, we observe in the time domain the coherent torsional dynamics that drives planarization of the excited state. Our interpretation is based on numerical modeling of the ground and excited state potential energy surfaces and simulation of wavepacket dynamics, which reveals two symmetric excited state deactivation pathways per oscillation period. We use the acquired knowledge on torsional dynamics to coherently control the excited state population with a pump-dump scheme, exploiting the non-stationary Franck-Condon overlap between ground and excited states.
authors.affiliation: Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cirmi
authors.forename: Daniele
authors.initials: D
authors.lastname: Brida
authors.forename: Alessio
authors.initials: A
authors.lastname: Gambetta
authors.forename: Manuel
authors.initials: M
authors.lastname: Piacenza
authors.forename: Fabio
authors.initials: F
authors.lastname: Della Sala
authors.forename: Laura
authors.initials: L
authors.lastname: Favaretto
authors.forename: Giulio
authors.initials: G
authors.lastname: Cerullo
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Lanzani
mesh_terms: D056004:Molecular Dynamics Simulation; D013876:Thiophenes / Q000737:chemistry*; D013997:Time Factors; D014732:Vibration
chemical_list: D013876:Thiophenes