title: Quantum transport in the FMO photosynthetic light-harvesting complex.
abstract: The very high light-harvesting efficiency of natural photosynthetic systems in conjunction with recent experiments, which showed quantum-coherent energy transfer in photosynthetic complexes, raised questions regarding the presence of non-trivial quantum effects in photosynthesis. Grover quantum search, quantum walks, and entanglement have been investigated as possible effects that lead to this efficiency. Here we explain the near-unit photosynthetic efficiency without invoking non-trivial quantum effects. Instead, we use non-equilibrium Green's functions, a mesoscopic method used to study transport in nano-conductors to compute the transmission function of the Fenna-Matthews-Olson (FMO) complex using an experimentally derived exciton Hamiltonian. The chlorosome antenna and the reaction center play the role of input and output contacts, connected to the FMO complex. We show that there are two channels for which the transmission is almost unity. Our analysis also revealed a dephasing-driven regulation mechanism that maintains the efficiency in the presence of varying dephasing potentials.
authors.affiliation: Democritus University of Thrace, Kimmeria Campus, 67100, Xanthi, Greece. ykar@ee.duth.gr.
authors.forename: Ioannis G
authors.initials: IG
authors.lastname: Karafyllidis
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism*; D008954:Models, Biological; D010788:Photosynthesis; D021381:Protein Transport
chemical_list: D001426:Bacterial Proteins; C086320:FMO bacteriochlorophyll protein, Bacteria; D045342:Light-Harvesting Protein Complexes
keywords: FMO complex; NEGF; Non equilibrium Green's Functions; Photosynthesis; Quantum transport