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Abstract

In this thesis, we investigate the excitation energy transfer process during photosynthesis in the Fenna-Matthews-Olson complex described by a phenomenological Liouville-von- Neumann equation in Lindblad form. In the first part, we focus on the effect of non-local superpositions in the initial excitations on the transport efficiency. We identify those non-local initial states that exhibit maximum efficiency for zero dephasing and find that the efficiency is robust over a broad regime of dephasing rates. In addition, we discuss the advantage of a trapping (exit) site other than the usual choice. In the second part, we investigate the correlations between the entry sites and the exit sites in terms of entanglement, quantum discord and mutual information for initial states found in the first part. We see that the high efficiency states show more correlations than the low efficiency states and recognize a connection between quantum correlations and a simple coherence measure. Furthermore, the structure of classical correlations is found to be related to a quantity based on the purity of a subsystem. Besides that, we give a proof of the equivalence of the relative entropy of entanglement and quantum discord in the zero- and single-excitation subspaces under assumptions valid in this model. Finally, we briefly investigate the effect of initial coherence on the correlations in a straightforward extension to higher excitations.