Dresden 2011 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 21: Electronic Spectroscopy I

MO 21.9: Vortrag

Donnerstag, 17. März 2011, 12:30–12:45, MER 02

Efficiency of energy transfer in the FMO complex under the influence of a Non-Markovian environment — •Christoph Kreisbeck¹, Mirta Rodriguez Pinilla², Birgit Hein¹, and Tobias Kramer¹ — ¹Institute for Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany — ²Instituto de Estructura de la Materia, Madrid, Spain

Laser spectroscopy experiments by Engel et al. (Nature 2007) and also by Collini et al. (Nature 2010) suggest that quantum coherent effects may be essential in the energy transfer in light-harvesting complexes despite their high operating temperatures. The interplay between coherent and environment assisted energy transfer leads to highly efficient transport to the reaction center. Strong coupling to the environment requires a non-Markovian approach and we use the hierarchical equations (HE) proposed by Ishizaki and Fleming in 2009, which includes properly the reorganization process. We compare the HE with the Markovian dynamics for different temperatures and a wide range of reorganization energies. For both cases the Markov limit overestimates thermalization, yielding higher efficiencies than the HE. Our results demonstrate that initial quantum beatings are important for the energy distribution but of limited influence to the efficiency. To overcome the long computation times of the numerically demanding HE we use the high-performance of graphics processing units (GPU) resulting in tremendous speedups (400 fold) compared to standard CPUs. Our efficient GPU implementation allows us to calculate nonlinear spectra of the FMO complex (see Birgit Hein).