The researchers found another unusuala feature of the behavior of an electric charge in a “strange metal”, which brings us one step closer to understanding the structure of the physical world at a basic level.
About 30 years ago, scientists discovered that metalsbased on copper oxide, called cuprates, have a number of strange properties. In addition to the fact that their electrical resistance drops to zero at higher temperatures than conventional superconductors, it changes with temperature in a linear fashion.
AT ordinary metals, the resistance increases onlyup to a certain limit, and then stabilizes and remains constant despite further heating. This mechanism is explained by the Fermi-liquid theory, which establishes the maximum scattering velocity of electrons upon collision with an atomic lattice. Cuprates don't obey this rule and scientists still don't know why. They only know that their strange behavior is due to fundamental constants: the Boltzmann constant and the Planck constant.
Over the past few years, a team of physicists fromBrown University studied electrical activity, in which the charge carriers are not electrons, but Cooper pairs, which can slide through the atomic lattice without resistance and behave like bosons, moving collectively.
In a new experiment, the researchers studiedfeatures of the behavior of these particles in cuprates. To do this, they used yttrium-barium-copper oxide, with tiny holes that create the metallic state of a Cooper pair. By cooling the material to a temperature just below its superconductivity limit, they observed that the conductivity of the Cooper bosons that form the Fermi liquid also exhibited a linear dependence on temperature.
According to scientists, this discovery will give scientists a newfood for thought and, perhaps, will help not only to explain the reasons for the unusual behavior of cuprates, but also to better understand the fundamental laws of the universe.
We also previously reported on the synthesis of a new metallic superconductor from niobium and germanium, in which electrons move not like ordinary particles, but like water through pipes.</p>