Finding hidden swirls of electric current shows that the material’s behavior matches standard theory
© XAVIER RAVINET/UNIGE
A misfit gang of superconducting materials may be losing their outsider status.
Certain copper-based compounds superconduct, or transmit electricity without resistance, at unusually high temperatures. It was thought that the standard theory of superconductivity, known as Bardeen-Cooper-Schrieffer theory, couldn’t explain these oddballs. But new evidence suggests that the standard theory applies despite the materials’ quirks, researchers report in the Dec. 8 Physical Review Letters.
All known superconductors must be chilled to work. Most must be cooled to temperatures that hover above absolute zero (–273.15° Celsius). But some copper-based superconductors work at temperatures above the boiling point of liquid nitrogen (around –196° C). Finding a superconductor that functions at even higher temperatures — above room temperature — could