Pigment vibrations drive photosynthetic energy transfer

摘要

During photosynthesis, antenna proteins position light-absorbing pigment molecules so that they direct the transfer of electronic energy toward a reaction center. Despite advances in technology and quantum physics, the mechanisms underlying the efficient process of energy transfer remain elusive. Vivek Tiwari et al. (pp. 1203-1208) examined whether small amplitude vibrations inside the pigments, known as nonadiabatic dynamics, contribute to photosynthetic energy transfer. Using a model that mathematically describes coupled vibrational and electronic motion, the authors demonstrate that when the so-called electronic energy gap of the antenna protein matches an internal pigment vibration, two coupled pigments vibrate out of phase, thus mixing their excited states and driving energy transfer. Such mixing, the authors report, can give rise to delocalized vibrational wavepackets with signatures of quantum coherence and energy transfer.