Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/213336

Title

Coherent vibronic coupling in light-harvesting complexes from photosynthetic marine algae

Author(s)

Richards, G. H.;  Wilk, K. E.;  Curmi, P. M. G.;  Quiney, H. M.;  Davis, J. A.

Abstract

Observations of long-lived coherences in photosynthetic light-harvesting complexes utilize short pulses with broad spectral bandwidths to coherently excite multiple transitions and coherent superpositions. In order to identify the role that such quantum effects might play in efficient energy transfer, however, an alternative approach is required. We have developed a technique for two-color photon echo spectroscopy to selectively excite the pathway of interest and measure its evolution in the absence of any other excitation. We use this technique to excite a coherence pathway in phycocyanin-645 from cryptophyte algae and measure the dynamics of this coherence. A decoherence time of 500 fs was measured, and clear signatures for strong coupling between the electronic states and phonon modes were observed, allowing coherent coupling between otherwise nonresonant transitions. This provides detailed experimental evidence of the long-lived coherences and the nature of the quantum mechanical interactions between electronic states and phonon modes in phycocyanin-645 from cryptophyte marine algae.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Engineering and Industrial Sciences. Centre for Atom Optics and Ultrafast Spectroscopy

Source

Journal of Physical Chemistry Letters, Vol. 3, no. 2 (Jan 2012), pp. 272-277

Publication year

2012

FOR Code(s)

02 Physical Sciences;  03 Chemical Sciences

Keyword(s)

Coherent vibronic coupling;  Energy transfer;  Light-harvesting complexes;  Marine algae;  Photosynthesis;  Quantum effects

Publisher

American Chemical Society

ISSN

1948-7185

Publisher URL

http://dx.doi.org/10.1021/jz201600f

Copyright

Copyright © 2012 American Chemical Society.

Additional information

The authors acknowledge supoprt from the Australian Research Council.

Peer reviewed