Experiment has now proved the existence of the predicted three-dimensional 'topological insulator' in the semiconducting alloy Bi 1−x Sb x. One of the triumphs of quantum mechanics in the ...

In an insulator the Fermi energy lies in the bandgap between the minimum of the conduction band and the maximum of the valence band. The situation changes at the surface of a 3D host (or the edge ...

For electricity to flow, you need a conductor. That plastic bottle, that’s an insulator, they don’t let electricity pass through. No, not that either, wood’s an insulator too. We’ve got to ...