Probing individual edge states with unprecedented precision

ingerprint of the current-carrying edge states occurring in novel materials such as topological insulators or 2-D materials. Physicists of the University of Basel present the new method together with American scientists in Nature Communications.

While insulators do not conduct electrical currents, some special materials exhibit peculiar electrical properties. Though not conducting through their bulk, their surfaces and edges may support electrical currents due to quantum mechanical effects, and do so even without causing losses. Such topological insulators have attracted great interest in recent years due to their remarkable properties. In particular, their robust edge states are very promising since they could lead to great technological advances.

Similar effects as the edge states of such topological insulators also appear when a two-dimensional metal is exposed to a strong magnetic field at low temperatures. When the so-called quantum Hall effect is realized, current is thought to flow only at the edges, where several conducting channels are formed.