title: Correlated Fluctuations and Intraband Dynamics of J-Aggregates Revealed by Combination of 2DES Schemes.
abstract: The intraband exciton dynamics of molecular aggregates is a crucial initial step to determine the possibly coherent nature of energy transfer and its implications for the ensuing interband relaxation pathways in strongly coupled excitonic systems. In this work, we fully characterize the intraband dynamics in linear J-aggregates of porphyrins, good model systems for multichromophoric assemblies in biological antenna complexes. Using different 2D electronic spectroscopy schemes together with Raman spectroscopy and theoretical modeling, we provide a full characterization of the inner structure of the main one-exciton band of the porphyrin aggregates. We find that the redistribution of population within the band occurs with a characteristic time of 280 fs and dominates the modulation of an electronic coherence. While we do not find that the coupling to vibrations significantly affects the dynamics of excitonic coherence, our results suggest that exciton fluctuations are nevertheless highly correlated.
authors.affiliation: Department of Chemical Sciences, University of Padova , Via Marzolo 1, Padova 35131, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bolzonello
authors.affiliation: Department of Physics, University of Trieste , Strada Costiera 11, Trieste 34151, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Fassioli
authors.affiliation: Department of Chemical Sciences, University of Padova , Via Marzolo 1, Padova 35131, Italy.
authors.forename: Elisabetta
authors.identifier: http://orcid.org/0000-0002-1019-9100
authors.initials: E
authors.lastname: Collini