Nonlocal Transport in the Quantum Spin Hall State

Abstract

Living on the Edge: Topological insulators are a recently described state of matter in which the bulk material is an insulator but with a metallic surface state that is protected by the topology of the Fermi surface. Roth et al. (p. 294 ; see the Perspective by Büttiker ) now show that the current flow on the surface takes place in edge states around the boundary of the sample. These are similar to the current transport in high-quality two-dimensional electron gases in high magnetic field, which confirms theoretical work on these materials.