Nature does not rely on long-lived electronic quantum coherence for photosynthetic energy transfer [Physics]
During the first steps of photosynthesis, the energy of impinging solar photons is transformed into electronic excitation
energy of the light-harvesting biomolecular complexes. The subsequent energy transfer to the reaction center is commonly rationalized
in terms of excitons moving on a grid of biomolecular chromophores on typical timescales
<100 fs. Today’s understanding of the energy transfer includes the fact that the excitons are delocalized over a few neighboring
sites, but the role of quantum coherence is considered as irrelevant for the transfer dynamics because it typically decays
within a few tens of femtoseconds. This orthodox picture of incoherent energy transfer between clusters of a few pigments
sharing delocalized excitons has been challenged by ultrafast optical spectroscopy experiments with the Fenna–Matthews–Olson
protein, in which interference oscillatory signals up to 1.5 ps were reported and interpreted as direct evidence of exceptionally
long-lived electronic quantum coherence. Here, we show that the optical 2D photon echo spectra of this complex at ambient
temperature in aqueous solution do not provide evidence of any long-lived electronic quantum coherence, but confirm the orthodox
view of rapidly decaying electronic quantum coherence on a timescale of 60 fs. Our results can be considered as generic and
give no hint that electronic quantum coherence plays any biofunctional role in real photoactive biomolecular complexes. Because
in this structurally well-defined protein the distances between bacteriochlorophylls are comparable to those of other light-harvesting
complexes, we anticipate that this finding is general and directly applies to even larger photoactive biomolecular complexes.
Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.
Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.