An international team of physicists from NUST MISIS, the Russian Quantum Center, the University of Karlsruhe and the University of Mainz from Germany have learned to simulate processes that can help decipher the mechanisms of photosynthesis. An article about this research was published in the journal Nature Communications.

Photosynthesis is most often understood as a set of processes of absorption, conversion and use of light energy in various reactions, including the conversion of carbon dioxide into organic matter with the release of oxygen. Due to the decrease in the number of plants on Earth, the reproduction of photosynthesis in artificial conditions is currently a very urgent task. But in order to repeat a process, you first need to understand it.

However, this problem turned out to be a tough nut to crack, and there is not enough power of computers around the world to find answers to some of its questions. Therefore, the researchers resorted to simulations using quantum computers.

“At the moment of its absorption by matter, light interacts with vibrations of interatomic bonds in molecules, in particular with those responsible for photosynthesis. The properties of such vibrations allow molecules to “store” a large number of quanta of light, that is, energy. It is also known that in the process of photosynthesis, a quantum of light is absorbed (the smallest value in measuring the energy of electromagnetic waves) – a photon, and its energy when interacting with matter is almost completely absorbed. The efficiency of this process is more than 50%. It is a very highly efficient process of converting light energy into energy “stored” in matter ”, – says Aleksey Ustinov, head of the Superconducting Metamaterials Laboratory at NUST MISIS and head of the group at the Russian Quantum Center.

In this case, artificial atoms – qubits – were taken as a “memory cell” of a quantum computer. They behave like natural particles, have the same structure at the quantum level. But their structure (and hence their physical properties) can be changed instantly. In particular, the distance between energy levels, that is, the amount of energy required for the transition of an artificial atom from one level to another. A necessary condition for quantum measurements is a low temperature – it was maintained at a level of 20 millikelvin, almost absolute zero! Such extreme “frost” is necessary so that thermal fluctuations do not interfere with the observation of quantum mechanical processes.

The term “superconducting” means that the material of a qubit has strictly zero electrical resistance when it reaches a temperature below a certain value. It is also necessary to neutralize unnecessary electron movements. To read the state of qubits (on which the calculation method in quantum computers is based), a change in the frequency of light was used.

A system in which there is only one photon and only one two-level system, that is, an artificial atom, can be calculated on an ordinary computer. But in reality there are many photons, they can interact with several artificial systems, and only a quantum computer allows calculations in a complex system similar to the natural process of photosynthesis.

Source: RIA Novosti