Solving Complex Chemical Reaction With Quantum Computers

Solving an Unsolved Mystery in Chemistry.

Solving Complex Chemical Reaction With Quantum Computers
Future quantum computers will be able to calculate the reaction mechanism of the enzyme nitrogenase. The image shows the active centre of the enzyme and a mathematical formula that is central for the calculation. (Visualisations: ETH Zurich)

Quantum computers can solve such challenging tasks that are partially the result of the fact that they are structured differently to classical computers. Instead of requiring many bits to assess each additional electron, quantum computers simply need one more qubit.

Currently, a quantum computer use on the order of 20 rudimentary qubits respectively. It will take at least another 5 years, or 10, to come with processors of more than 100 high-quality qubits.

Although, Science and the IT industry have higher expectations from quantum computing. Even scientists at the ETH Zurich have now come up with a complex example. It demonstrates what quantum computers can do in the future.

With the help of a quantum computer, scientists have evaluated a complex chemical reaction. They show that quantum computers can indeed deliver scientifically relevant results.

Matthias Troyer, who is Professor of Computational Physics at ETH Zurich said, “To accomplish this, the quantum computer must be of a moderate size. The mechanism of this reaction would be nearly impossible to assess with a classical supercomputer alone especially if the results are to be sufficiently precise.”

For the study, scientists chose a particularly complex chemical reaction as the example for their study. They choose a special enzyme known as a nitrogenase, where certain microorganisms are able to split atmospheric nitrogen molecules. Although, it is still a mystery how the chemical reaction occurs with single nitrogen atoms.

Here, complexity is a reflection of how many electrons interact with each other over a long distance. The more electrons a researcher needs to take into account, the more sophisticated the computations.

Reiher said, “Existing methods and classical supercomputers can be used to assess molecules with about 50 strongly interacting electrons at most. However, there is a significantly more such electron at the active center of a nitrogenase enzyme. Because with classical computers the effort required to evaluate a molecule doubles with each additional electron, an unrealistic amount of computational power is needed.”

Scientists also affirmed that quantum computers cannot handle all tasks. They need to be thought more like a co-processor capable of taking over particular tasks from classical computers. It will also them to become more efficient.

Although to explain nitrogenase reaction, quantum computers will be able to calculate how the electrons are distributed within a specific molecular structure. They will also require more than just information about the electron distribution in a single molecular structure.

Troyer said, “In order for quantum computers to be of use in solving these kinds of problems, they will first need to be mass-produced, thereby allowing computations to take place on multiple computers at the same time.”