Fenna–Matthews–Olson complex

[2] It appears in green sulfur bacteria and mediates the excitation energy transfer from light-harvesting chlorosomes to the membrane-embedded bacterial reaction center (bRC).

[12] Light harvesting in photosynthesis employs both classical and quantum mechanical processes with an energy efficiency of almost 100 percent.

Because energy can exist in a superposition of states, it can travel all routes within a material at the same time.

When a photon finds the correct destination, the superposition collapses, making the energy available.

Anderson localization prevents the spread of quantum states in random media.

The proposal of Engel is still debated in literature with the suggestion that the original experiments were interpreted incorrectly assigning the spectral oscillations to electronic coherences instead of ground-state vibrational coherences, which will naturally be expected to live longer due to the narrower spectral width of vibrational transitions.

Figure 1. The FMO protein trimer. [ 1 ] The BChl a molecules are depicted in green, the central magnesium atom in red and the protein in grey ("cartoons" representation). Each monomer contains bacteriochlorophylls.