Intraband dynamics and exciton trapping in the LH2 complex of Rhodopseudomonas acidophila

Thyrhaug, E., Schröter, M., Bukartė, E., Kühn, O., Cogdell, R. , Hauer, J. and Zigmantas, D. (2021) Intraband dynamics and exciton trapping in the LH2 complex of Rhodopseudomonas acidophila. Journal of Chemical Physics, 154(4), 045102. (doi: 10.1063/5.0033802) (PMID:33514092)

Abstract

Over the last several decades, the light-harvesting protein complexes of purple bacteria have been among the most popular model systems for energy transport in excitonic systems in the weak and intermediate intermolecular coupling regime. Despite this extensive body of scientific work, significant questions regarding the excitonic states and the photo-induced dynamics remain. Here, we address the low-temperature electronic structure and excitation dynamics in the light-harvesting complex 2 of Rhodopseudomonas acidophila by two-dimensional electronic spectroscopy. We find that, although at cryogenic temperature energy relaxation is very rapid, exciton mobility is limited over a significant range of excitation energies. This points to the presence of a sub-200 fs, spatially local energy-relaxation mechanism and suggests that local trapping might contribute substantially more in cryogenic experiments than under physiological conditions where the thermal energy is comparable to or larger than the static disorder.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cogdell, Professor Richard
• Authors: Thyrhaug, E., Schröter, M., Bukartė, E., Kühn, O., Cogdell, R., Hauer, J., and Zigmantas, D.
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Journal Name: Journal of Chemical Physics
• Publisher: American Institute of Physics
• ISSN: 0021-9606
• ISSN (Online): 1089-7690
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Journal of Chemical Physics 154(4):045102
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
172826		DNA-directed construction of three-dimensional photosynthetic assemblies	Alasdair Clark	Biotechnology and Biological Sciences Research Council (BBSRC)	BB/N016734/1	ENG - Biomedical Engineering