Photosynthesis Relies on Quantum Coherence

When Will They Cry Uncle?

It is no secret that nature’s process of photosynthesis—which harnesses the energy in sunlight—is astonishingly efficient. And researchers have known for years that quantum mechanisms play a role in the protein antenna farms deployed in these marvelous molecular machines. Now new research, based on a experimental technique that tracks these proteins at the femtosecond level (there are a million billion femtoseconds in a second), elucidates some of these quantum mechanisms and, as usual, the results are surprising.

Photosynthesis begins with special proteins that capture and transmit the energy from sunlight. The new research shows that these proteins use specific energy-transfer pathways that apparently are adaptive to the current conditions. These pathways are protein-specific and time-varying.

And part of the reason why these energy-transfer processes are so efficient is that they are coordinated. This quantum coherence is long-lived, persisting for hundreds of femtoseconds. As one of the researchers put it:

These results show that coherence, a genuine quantum effect of superposition of states, is responsible for maintaining high levels of transport efficiency in biological systems, even while they adapt their energy transport pathways due to environmental influences.

It would be an abuse of science to say the evolution of such systems is a fact, or likely. I don’t care if evolution is true or not, but from a strictly scientific perspective (which is not how the theory is motivated or evaluated), the idea is, to be frank, just silly.

These new results continue to make that clear.