Surprise graphene discovery could unlock secrets of superconductivity
A sandwich of two graphene layers can conduct electrons without resistance if they are twisted at a ‘magic angle’', physicists have discovered. The finding could prove to be a significant step in the decades-long search for room-temperature superconductors.
Most superconductors work only at temperatures close to absolute zero. Even ‘high-temperature’ superconductors are called that only in a relative sense: the highest temperature at which they conduct electricity without resistance is around −140 ºC. A material that displayed the property at room temperature — eliminating the need for expensive cooling — could revolutionize energy transmission, medical scanners and transport.
Physicists now report that arranging two layers of atom-thick graphene so that the pattern of their carbon atoms is offset by an angle of 1.1º makes the material a superconductor. And although the system still needed to be cooled to 1.7 degrees above absolute zero, the results suggest that it may conduct electricity much like known high-temperature superconductors — and that has physicists excited. The findings are published in two Nature papers1,2 on 5 March.