Exciton dynamics of chlorosomal light harvesting complex probed by two-dimensional electronic spectroscopy

초록

Photosynthetic light harvesting complexes have gar-nered much interest because it has the potential of being used for harnessing the solar energy. Recently, it has been reported that long-lived quantum coherence might play an important role in highly efficient energy transfer in natural light harvesting complexes [1]. Chlorosome, which is the most efficient light-harvesting antenna system found in nature, consists of self-assembled aggregates of bacteriochlorophyll (BChl) pigments without any protein involved, which is in contrast to general photosynthetic complexes consisting of pigments held by protein scaffold [2]. Considering the unique supramolecular structure, it would be of much interest to examine how energy transfer occurs in chlorosome, especially in comparison with other types of natural photosynthetic complexes. In this work, we investigate energy transfer dynamics among the exciton states of chlorosome using two-dimensional electronic spectroscopy (2D-ES) at cryogenic temperature.