Michael Moyer writes in Scientific American:
As nature’s own solar cells, plants convert sunlight into energy via photosynthesis. New details are emerging about how the process is able to exploit the strange behavior of quantum systems, which could lead to entirely novel approaches to capturing usable light from the sun.
All photosynthetic organisms use protein-based “antennas” in their cells to capture incoming light, convert it to energy and direct that energy to reaction centers — critical trigger molecules that release electrons and get the chemical conversion rolling. These antennas must strike a difficult balance: they must be broad enough to absorb as much sunlight as possible yet not grow so large that they impair their own ability to shuttle the energy on to the reaction centers.
This is where quantum mechanics becomes useful. Quantum systems can exist in a superposition, or mixture, of many different states at once. What’s more, these states can interfere with one another — adding constructively at some points, subtracting at others. If the energy going into the antennas could be broken into an elaborate superposition and made to interfere constructively with itself, it could be transported to the reaction center with nearly 100 percent efficiency.