Quantum Coherence in Photosynthetic Light Harvesting

Recent two-dimensional (2D) electronic spectroscopic experiments revealed that electronic energy transfer in photosynthetic light harvesting involves long-lived quantum coherence among electronic excitations of pigments. These findings have led to the suggestion that quantum coherence might play a role in achieving the remarkable quantum efficiency of photosynthetic light harvesting. Further, this speculation has led to much effort being devoted to elucidation of the quantum mechanisms of the photosynthetic excitation energy transfer (EET). In this review, we provide an overview of recent experimental and theoretical investigations of photosynthetic electronic energy transfer, specifically addressing underlying mechanisms of the observed long-lived coherence and its potential roles in photosynthetic light harvesting. We close with some thoughts on directions for future developments in this area. 333 A nn u. R ev . C on de ns . M at te r Ph ys . 2 01 2. 3: 33 336 1. D ow nl oa de d fr om w w w .a nn ua lr ev ie w s. or g by U ni ve rs ity o f C al if or ni a B er ke le y on 0 7/ 09 /1 2. F or p er so na l u se o nl y.