Quantum Energy Transport Through Genetic Engineering

MIT engineers use viruses to demonstrate exciton movement similar to photosynthesis.

MIT rendering of a virus’ chromophores (depicted as red) which absorb photons (depicted as glowing white). Adjusting the spacing and locations of chromophores allows energy to jump from one chromophore to the next faster and more efficiently.

MIT rendering of a virus’s chromophores (depicted as red) which absorb photons (depicted as glowing white). Adjusting the spacing and locations of chromophores allows energy to jump from one chromophore to the next faster and more efficiently.

Over billions of years, nature has perfected photosynthesis, achieving efficiencies much higher than even the best man-made solar cells.

One method plants use to transfer solar energy is responsible for this efficiency; namely, the exotic effects of quantum mechanics also known as “quantum weirdness.” 

These effects include the ability of a particle to exist in more than one place at a time. Engineers at MIT are using this effect to achieve a significant efficiency boost in a light-harvesting system.

What is odd is that MIT isn’t looking to high-tech materials or microchips to achieve this improvement. Instead, they are using genetically engineered viruses.

In photosynthesis, a photon hits a receptor called a chromophore, which in turn produces a quantum particle of energy called an exciton. This exciton jumps from one chromophore to another until it reaches a reaction center where it is harnessed into the chemical energy which supports life.

However, the pathway to transfer energy between the chromophores to the reaction center is random and inefficient. That is, unless the transfer takes advantage of quantum effects which allow it to take multiple pathways at once and select the best ones. 

To achieve this efficient movement of excitons, the chromophores must have the right arrangement and amount of space between them. This is known as the “Quantum Goldilocks Effect” according to Seth Lloyd, professor of mechanical engineering at MIT and an expert on quantum theory and its potential applications.

This is where the virus comes in.

Using bioengineering techniques, the team was able to bond multiple synthetic chromophores (organic dyes) to the virus. The researchers were then able to produce many varieties of the virus with slightly different spacing between those synthetic chromophores to determine which ones performed best.

Once the virus was engineered, the team was able to use laser spectroscopy and dynamical modeling to monitor the light-harvesting process.

The team demonstrated that the new viruses were making use of quantum coherence to improve the transportation of excitons. 

In the end, the speed of the exciton transfer more than doubled and the distance traveled by the exciton increased before it dissipated.

These results are preliminary but the MIT team suggests it points to potential ways to reduce the cost and increase the efficiency of solar cells and light-driven catalysis.

It should be noted that the engineered viruses currently only collect and transport energy from incoming light. The viruses do not yet harness the power through photosynthesis. However, the MIT researchers say that this could be done by adding a reaction center to the virus.

The paper detailing the team’s work in coupling quantum research and genetic manipulation is published in the journal Nature Materials.