High-temperature superconductivity was first discovered in 1986, but the physics underlying the phenomenon is still shrouded in mystery. In 1990, researchers discovered that, above their superconducting transition temperatures, the archetypal high-temperature superconductors, the cuprates, can behave as “strange” metals whose electrical resistance does not vary as expected with temperature. Now, researchers led by Arkady Shekhter of the National High Magnetic Field Laboratory in the US have shown that the same strange behaviour applies to the way their resistance varies with magnetic field. The results could have fundamental implications for our understanding of the nature of superconductivity and far beyond.
While the traditional BCS theory of superconductivity (named after its developers Bardeen, Cooper and Schrieffer) cannot explain superconductivity above about 30 K, cuprates have been shown to retain their superconducting properties at temperatures of up to 130 K. But even when the materials do finally relinquish their superconductivity, cuprates are still puzzling because of their unusual metallic behaviour.To read more, click here.