Future challenges in quantum efficiency

Uzi Landman led an interesting discussion this evening. He is very amusing. Here are a few random notes.

"People believe anything if you use words like nano and quantum."
Dean Koontz, Relentness

"The scientist is not the person who gives the right answers but asks the right questions." Claude Levi-Stauss (1908- )

Photosynthesis cycles involves water splitting.
Manganese oxide cube only determined in 2005. Debatable whether this structure can actually be determined with x-ray crystallography.
Where is the water? How many waters? Why is a cube? The cube is a common structural motif. Does symmetry breaking play a role?
For more on this see an earlier post which gives a few of my thoughts on some of the open questions.

Reaction Centre has to absorb 4 photons to establish a large enough potential to do the oxidation.
This system is extremely specific; not a spherical cow.

Why manganese? (Proc. Roy. Soc. paper a few years ago.)

Measure higher order correlation functions on single molecules to determine whether there are truly non-trivial quantum effects.

Major challenge is to assemble in the lab something that self regulates/repairs.

Packing density in light harvesters are optimised to match the photon flux with the turnover rate of biochemical reactions. Components need to be close but not too close.

Bacteriochlorophyls in LH1 and LH2 exhibit super-radiance consistent with a delocalisation of excitons over 2-4 chromophores.

Does redundancy matter?

Theorists should pay more attention to common structural motifs.

Elliot Montroll argued Photosynthetic system should be two-dimensional.
(PNAS in 1974) This was based on arguments involving probability of return to origin for random walks.

It would be good if someone wrote a "Resource paper" on this subject.

The whole question of charge transport in DNA got off to a bad start because of dubious experimental results. Views ranged from superconductor to insulator.
It turns out to be interesting because the diffusion of counterions in the solvent is what dominates the transport.

To what extent does a system need a blueprint to self-assemble?