Stuttgart 2012 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 15: Quanteneffekte: Verschränkung und Dekohärenz 1

Q 15.5: Talk

Monday, March 12, 2012, 17:30–17:45, V7.01

Coherent Dynamics under Ambient Conditions in Photosynthesis — •Zachary Walters — Max Planck Institute for Physics of Complex Systems, Noethnitzer Strasse 38, Dresden, Sachsen, Deutschland

Photosynthesis requires efficient transfer of electronic excitation from molecular complexes where sunlight is absorbed to reaction centers where the energy can be harvested. Recent experiments with photosynthetic antenna complexes have found that this process involves long-lived coherence between constituent pigment molecules, or chromophores, which make up these complexes. Expected to decay in less than 100 fs, coherences were observed to persist for picosecond timescales, despite having no apparent separation between system and environment. This talk presents a simple theory of long-lived coherence in the limit of strong interactions between a system and a thermal environment, yielding arbitrarily long lifetimes in both the high- and low temperature limit. Spectral lineshapes and excitonic transfer times are shown to give good agreement with experiment for the PE545 antenna complex of the cryptophyte algae CS24.