U.S. scientists discover strange metals challenging conductivity theories

Scientists in the United States have discovered new kinds of metals that behave in unexpected ways. These findings challenge a theory that has been used for more than 60 years to explain how electricity works in metals. The long-standing theory, known as the "Fermi liquid" theory, has been a major part of condensed matter physics. It describes how electrons, which repel each other, move together in groups called quasiparticles. This helps them carry electric charge effectively. However, the researchers noted that many of these new materials, referred to as "strange metals," do not follow this theory. In these strange metals, electricity does not move with discrete charges like it does in typical metals. One interesting feature of these materials is how their resistance changes when cooled. In typical metals, resistance changes in a predictable way with temperature. But in strange metals, this relationship is linear at low temperatures, which is very different from what was expected.