EXCITON’S ORGANIZED MOTION. “Engel et al., have demonstrated… that surprisingly long-lived (>660 fs) quantum coherences between excitonic states play an important role in the dynamics of energy transfer in photosynthetic complexes—i.e., the energy transfer is described by wavelike coherent motion instead of incoherent hopping.”
http://www.sciencemag.org/content/316/5830/1462