Quantum effects in energy and charge transfer in an artificial photosynthetic complex

Journal Article · Tue Jun 28 00:00:00 EDT 2011 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3600341· OSTI ID:21560308

Ghosh, Pulak Kumar ^[1]; Smirnov, Anatoly Yu; Nori, Franco ^[1]

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1. Advanced Science Institute, RIKEN, Wako, Saitama 351-0198 (Japan)

We investigate the quantum dynamics of energy and charge transfer in a wheel-shaped artificial photosynthetic antenna-reaction center complex. This complex consists of six light-harvesting chromophores and an electron-acceptor fullerene. To describe quantum effects on a femtosecond time scale, we derive the set of exact non-Markovian equations for the Heisenberg operators of this photosynthetic complex in contact with a Gaussian heat bath. With these equations we can analyze the regime of strong system-bath interactions, where reorganization energies are of the order of the intersite exciton couplings. We show that the energy of the initially excited antenna chromophores is efficiently funneled to the porphyrin-fullerene reaction center, where a charge-separated state is set up in a few picoseconds, with a quantum yield of the order of 95%. In the single-exciton regime, with one antenna chromophore being initially excited, we observe quantum beatings of energy between two resonant antenna chromophores with a decoherence time of {approx}100 fs. We also analyze the double-exciton regime, when two porphyrin molecules involved in the reaction center are initially excited. In this regime we obtain pronounced quantum oscillations of the charge on the fullerene molecule with a decoherence time of about 20 fs (at liquid nitrogen temperatures). These results show a way to directly detect quantum effects in artificial photosynthetic systems.

• OSTI ID: 21560308
• Journal Information: Journal of Chemical Physics, Vol. 134, Issue 24; Other Information: DOI: 10.1063/1.3600341; (c) 2011 American Institute of Physics; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANTENNAS
BINDING ENERGY
CHARGE EXCHANGE
COMPLEXES
ELECTRONS
EQUATIONS
FULLERENES
HEAT
INTERACTIONS
LIQUIDS
MOLECULES
NITROGEN
OSCILLATIONS
PHOTON-MOLECULE COLLISIONS
PHOTOSYNTHESIS
PORPHYRINS
REACTION KINETICS
CARBON
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
COLLISIONS
ELECTRICAL EQUIPMENT
ELEMENTARY PARTICLES
ELEMENTS
ENERGY
EQUIPMENT
FERMIONS
FLUIDS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
KINETICS
LEPTONS
MOLECULE COLLISIONS
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTON COLLISIONS
SYNTHESIS