Superconductor May Hide Long-sought Secret - Science News: To probe the material, Yoichi Ando of Osaka University and colleagues in Japan injected current into it using a gold wire. This excited electrons at the surface, creating ripples of energy. Conventional superconductors have a dead spot in their surfaces that prevents low-energy, slow-wobbling ripples from forming. But a close look at this material revealed a sea of waves bouncing up and down both quickly and slowly.
Ando says that this pattern of ripples is “unambiguous evidence” of a type of superconductivity never seen before: topological superconductivity, in which electrons become waves molded into a complex shape that resembles the outside of a doughnut. These waves, says Ando, seem to be behaving like exotic two-dimensional particles at the surface of the material — specifically, Majorana fermions.
“This is the best evidence so far for Majorana fermions in a solid material,” says Taylor Hughes, a theoretical physicist at the University of Illinois at Urbana-Champaign.