All That Matters

There is a lot of buzz in the physics community about a new topological insulator: samarium hexaboride, SmB₆. The reason why any major discovery about topological insulators seems to be big news is that these materials have some unique electrical characteristics that make them not only very interesting from a fundamental point of view but also for electronic applications.

Topological insulators are electrically insulating in their interior, but at the surface they do conduct current. Moreover, the surface currents are topologically protected (hence the name), which means that the electrons that carry those currents don’t veer off the track easily and maintain their properties over long distance. Although a number of topological insulator compounds are known, the problem so far has been that it has been difficult to fabricate these with sufficient purity such that the interior was indeed insulating. This has been a problem, as the electrical current inside the materials just overwhelms the surface properties. […]