Until recently, physicists believed that all existing superconductors in the world can be divided into two types – the type of charge density waves that pass through them. But now there are superconducting materials of the third type.
Charge density waves belong to the so-called standing waves – they are registered in some crystals when the temperature decreases due to the displacement of electrons and ions. This is an insignificant offset, which is nevertheless sufficient for the charge density in a crystal to be distributed to create a superstructure.
Until now, physicists believed that there were only two types of charge density waves – s and d. But the authors of a new study, which appeared on the pages of Nature Physics, proved the existence of g waves.
The experiments that led to the discovery were carried out with the Sr2RuO4 compound cooled to a temperature close to absolute zero. The compound was found to be a two-component superconducting material with such a complex electron coupling that it could not be described by conventional s and d waves. Physicists are sure that there are other types of superconductors that have yet to be discovered by science.