Monday, December 13, 2010
Power Plants: Engineers Mimic Photosynthesis to Harvest Light Energy: Scientific American: Earlier research found that photosynthesis takes advantage of an effect known as quantum coherence. In one study researchers found that the energy absorbed by a chromophore travels through multiple networks at the same time in order to take the quickest path. Other research observed that "noise," or random fluctuations, at the quantum level helps move energy from chromophores to the reaction centers of photosynthesis. Building on this work, Cao and M.I.T. chemist Robert Silbey modeled a light-harvesting system in green sulfur bacteria and found that photosynthesis is most efficient when there is an intermediate amount of noise in the system. "In experimental conditions one always tries to reduce noise," Cao says, "but in a quantum mechanical system, it's actually useful to have some noise."