0000000000362554
AUTHOR
Claudia Roos
showing 2 related works from this author
The temperature dependence of vibronic lineshapes: linear electron-phonon coupling.
2014
We calculate the effect of a linear electron-phonon coupling on vibronic transitions of dye molecules of arbitrary complexity. With the assumption of known vibronic frequencies (for instance from quantum-chemical calculations), we give expressions for the absorption or emission lineshapes in a second-order cumulant expansion. We show that the results coincide with those obtained from generalized Redfield theory if one uses the time-local version of the theory and applies the secular approximation. Furthermore, the theory allows to go beyond the Huang-Rhys approximation and can be used to incorporate Dushinsky effects in the treatment of the temperature dependence of optical spectra. We cons…
Emergence of Coherence through Variation of Intermolecular Distances in a Series of Molecular Dimers
2015
Quantum coherences between electronically excited molecules are a signature of entanglement and play an important role for energy transport in molecular assemblies. Here we monitor and analyze for a homologous series of molecular dimers embedded in a solid host the emergence of coherence with decreasing intermolecular distance by single-molecule spectroscopy and quantum chemistry. Coherent signatures appear as an enhancement of the purely electronic transitions in the dimers which is reflected by changes of fluorescence spectra and lifetimes. Effects that destroy the coherence are the coupling to the surroundings and to vibrational excitations. Complementary information is provided by excit…