View of the bismuthene film through the scanning tunnelling microscope. The honeycomb structure of the material (blue) is visible, analogous to graphene. A conducting edge channel (white) forms at the edge of the insulating film (on the right). Credit: Felix Reis It's ultra-thin, electrically conducting at the edge and highly insulating within -- and all that at room temperature: Physicists from the University of Würzburg have developed a promising new material. The material class of topological insulators is presently the focus of international solids research. These materials are electrically insulating within, because the electrons maintain strong bonds to the atoms. At their surfaces, however, they are conductive due to quantum effects. What is more: The electron has a built-in compass needle, the spin, whose orientation is capable of transmitting information very efficiently. It is protected against scattering when moving through these surface channels. Wi...