Origin of Long-Lived Coherences in Light-Harvesting Complexes
- Author(s)
- Niklas Christensson, Harald Kauffmann, Tönu Pullerits, Tomas Mancal
- Abstract
A vibronic exciton model is applied to explain the long-lived oscillatory features in the two-dimensional (2D) electronic spectra of the Fenna-Matthews-Olson (FMO) complex. Using experimentally determined parameters and uncorrelated site energy fluctuations, the model predicts oscillations with dephasing times of 1.3 ps at 77 K, which is in a good agreement with the experimental results. These long-lived oscillations originate from the coherent superposition of vibronic exciton states with dominant contributions from vibrational excitations on the same pigment. The oscillations obtain a large amplitude due to excitonic intensity borrowing, which gives transitions with strong vibronic character a significant intensity despite the small Huang-Rhys factor. Purely electronic coherences are found to decay on a 200 fs time scale.
- Organisation(s)
- Electronic Properties of Materials
- External organisation(s)
- Lund University, Charles University Prague, Technische Universität Wien
- Journal
- The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical
- Volume
- 116
- Pages
- 7449-7454
- No. of pages
- 6
- ISSN
- 1520-6106
- DOI
- https://doi.org/10.1021/jp304649c
- Publication date
- 2012
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 104017 Physical chemistry, 1030 Physics, Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/origin-of-longlived-coherences-in-lightharvesting-complexes(d779caab-0fe1-4a5e-9761-63a5d896f6ed).html