Correlated protein environments drive quantum coherence lifetimes in photosynthetic pigment-protein complexes

Rolczynski, B. S. et al. (2018) Correlated protein environments drive quantum coherence lifetimes in photosynthetic pigment-protein complexes. Chem, 4(1), pp. 138-149. (doi: 10.1016/j.chempr.2017.12.009)

Abstract

Summary: Early reports of long-lived quantum beating signals in photosynthetic pigment-protein complexes were interpreted to suggest that electronic coherence benefits from protection by the protein, but many subsequent studies have suggested instead that vibrational or vibronic contributions are responsible for the observed signals. Here, we devised two 2D-spectroscopy methods to observe how each exciton is perturbed by its nuclear environment in a photosynthetic complex. The first approach simultaneously monitors each exciton's energy fluctuations over time to obtain its time-dependent electronic-nuclear interactions. The second method isolates evidence of coupled interexcitonic environmental motions. The techniques are validated with Nile Blue A and subsequently used on the Fenna-Matthews-Olson (FMO) complex. The FMO data reveal that each exciton experiences nearly identical spectral motion after excitation and that spectral motion of one excited exciton induces similar motion on unpopulated neighboring excitonic states. These synchronized and correlated spectral dynamics prolong coherences in the FMO complex after femtosecond excitation.

• Item Type: Articles
• Additional Information: B.S.R., H.Z., V.P.S., P.N., A.R.G., J.R.C., and G.S.E. would like to thank the Materials Research Science and Engineering Centers (DMR 14- 20709), the Air Force Office of Scientific Research (grant no. FA9550-14-1-0367 ), the Department of Defense Vannevar Bush Fellowship (grant no. N00014-16-1-2513), the Camille and Henry Dreyfus Foundation, and the Sloan Foundation for partially supporting the work in this publication. K.A., A.T.G., and R.J.C. gratefully acknowledge funding fr om the Photosynthetic Antenna Research Center, an Energy Frontier Research Center funded by the Basic Energy Sciences program of the US Department of Energy Office of Science,under award no. DE-SC0001035. S.K. and S.-H.Y. were supported by Qatar National Research Fund exceptional grant NPRPX-107-1-027.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cogdell, Professor Richard and Gardiner, Dr Alastair and Ashraf, Mr Khuram
• Authors: Rolczynski, B. S., Zheng, H., Singh, V. P., Navotnaya, P., Ginzburg, A. R., Caram, J. R., Ashraf, K., Gardiner, A. T., Yeh, S.-H., Kais, S., Cogdell, R. J., and Engel, G. S.
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Journal Name: Chem
• Publisher: Elsevier (Cell Press)
• ISSN: 2451-9308
• ISSN (Online): 2451-9294