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SYMN: Intersectional Symposium Transport and Spectroscopy in Molecular Nanostructures

SYMN 1: Transport and Spectroscopy in Molecular Nanostructures

SYMN 1.5: Hauptvortrag

Mittwoch, 16. März 2011, 12:30–13:00, HSZ 01

How do algae use quantum mechanics to harvest light for photosynthesis? — •Gregory Scholes — University of Toronto, Toronto, Canada

Light-harvesting in photosynthesis involves amplification and regulation of light capture by reaction centers using energy transfer from antenna proteins. Efficient energy transfer among specialized antenna proteins enables organisms to adapt to local solar spectra (e.g. at various depths in the ocean) and to function even under quite low light fluxes. The key biophysical processes at play have been discovered by investigating electronic energy transfer in a variety of photosynthetic proteins. A new twist on this old problem is suggested by recent research that provides evidence that these dynamics can involve quantum-coherence, even at ambient temperature conditions. Our experiments, using two-dimensional photon echo spectroscopy, have revealed that in light-harvesting antenna proteins isolated from a family of marine cryptophyte algae, quantum-coherence effectively 'wires' together the light-absorbing molecules in order to facilitate efficient long-range energy transfer [1]. In this talk I will describe the measurement, using 2D-photon echo spectroscopy, of quantum-coherence in energy transfer and I will report new insights into the mechanism underpinning the process.

[1] E. Collini, C. Y. Wong, K. E. Wilk, P. M. G. Curmi, P. Brumer, and G. D. Scholes, "Coherently wired light-harvesting in photosynthetic marine algae at ambient temperature", Nature 463, 644-648 (2010).