The quantum effects of the FMO complex (photosynthetic light harvesting complex found in green sulfur bacteria) have been well studied as well as the quantum effects in other photosynthetic systems. One of the most common hypotheses for explaining these phenomenon (focusing on FMO complex) is Environment-Assisted Quantum Transport (ENAQT) originally described by Rebentrost et al.. This mechanism describes how certain quantum networks can "use" decoherence and environment effects to improve the efficiency of quantum transport. Note that the quantum effectss arise from the transport of excitons from one pigment (chlorophyll) in the complex to another. (There is a question that discusses the quantum effects of the FMO complex in a little more detail).
Given that this mechanism allows for quantum effects to take place at room temperatures without the negative effects of decoherence, are their any applications for quantum computing? There are some examples of artificial systems that utilize ENAQT and related quantum effects. However, they present biomimetic solar cells as a potential application and do not focus on the applications in quantum computing.
Originally, it was hypothesized that the FMO complex performs a Grover's search algorithm, however, from what I understand, it has now since been showed that this is not true.
There have been a couple studies that use chromophores and substrates not found in biology (will add references later). However, I would like to focus on systems that use a biological substrate.
Even for biological substrates there are a couple examples of engineered systems that use ENAQT. For example, a virus-based system was developed using genetic engineering. A DNA-based excitonic circuit was also developed. However, most of these examples present photovoltaics as a main example and not quantum computing.
Vattay and KauffmanVattay and Kauffman was (AFAIK) the first to study the quantum effects as quantum biological computing, and proposed a method of engineering a system similar to the FMO complex for quantum computing.
How could we use this mechanism to build new types of computers? In the light harvesting case the task of the system is to transport the exciton the fastest possible way to the reaction center whose position is known. In a computational task we usually would like to find the minimum of some complex function $f_n$. For the simplicity let this function have only discrete values from 0 to K. If we are able to map the values of this function to the electrostatic site energies of the chromophores $H_{nn} = \epsilon_0 f_n$ and we deploy reaction centers near to them trapping the excitons with some rate $κ$ and can access the current at each reaction center it will be proportional with the probability to find the exciton on the chromophore $j_n ∼ κ\rho_{nn}$.
How can the quantum effects of the FMO complex be used on a biological substrate for quantum computing? Given that the quantum effects occur due to the transport of excitons on network structures, could ENAQT provide more efficient implementations of network-based algorithms (ex: shortest path, traveling salesman, etc.)?
P.S. I will add more relevant references if needed. Also, feel free to add relevant references as well.