Using 12 qubits of a quantum processor, the researchers were able to simulate the isomerization of diazene.
A team of engineers from Google AI Quantum announced the first successful quantum simulation of a chemical reaction. This was done using a 54-qubit Sycamore quantum processor. An article about the experiment was published in Science.
Quantum chemistry is considered one of the most promising fields of application for quantum computing. The greatest successes in this area have been achieved by specialists from IBM and Google. Previously, using processors consisting of several qubits, it was already possible to calculate the structure of not very complex molecules (for example, beryllium hydride BeH2).
To simulate the reaction, the authors of the work took one of the simplest known chemical processes - isomerization of diazene, a substance with the chemical formula N2H2. Such a reaction may look quite simple from the point of view of "classical" science, but at the quantum level a whole complex of difficult-to-predict things is taking place.
Sycamore has done an excellent job of this simulation, accurately describing the changes in the position of hydrogen atoms in the molecule during the formation of various diazene isomers. Only 12 of 54 Sycamore processor qubits were used for calculations - but this is already twice as many as in previous attempts to simulate quantum chemical processes.
Also, in the calculations, the hybrid algorithm VQE (variational quantum eigensolver, “variational quantum method of searching for eigenvalues”) was used. Its essence lies in the search for the minimum of a quantity that can be calculated using a quantum computer - for example, the energies of molecules and individual atoms. Such an algorithm makes it possible to carry out calculations in a matter of minutes, for which an ordinary supercomputer can take far more than one year.
The application of such an algorithm to quantum qubits opens up wide possibilities in various fields of science and technology. In this way, high-strength materials can be selected or the potential efficacy of pharmaceuticals can be calculated.
Earlier we wrote about the discovery of "quantum negativity", will help in the development of ultra-precise measuring devices, as well as about the strange behavior of positronium particles, which physicists have not been able to explain.