Vibrations, Coherence and Biology. The environment matters

Abstract:

The possibility that coherence may be exploited in biological processes has opened up new avenues of exploration at the interface of physics and biology. Recent observations of oscillatory features in the optical response of photosynthetic complexes have been interpreted as evidence for surprisingly long-lasting (ps) electronic coherences which coexist with energy transport.

Quasi-coherent exciton dynamics may play a key role in the often remarkable efficiency of light-harvesting in nature photosynthesis. However, the origins of these robust coherences are not currently understood. Here we show that non-trivial spectral structures of environmental fluctuations can lead to the spontaneous generation and sustenance of both oscillatory energy transport and electronic coherence on comparable timescales and also explain how the vibrational environment may collaborate with electronic coherence to facilitate optimal excitation energy transport. The general lessons from these observations will be outlined.