What is a topological material?
The most interesting topological materials are topological insulators, which are materials that are insulating in the bulk, but conducting on the surface. In these materials, the conducting channels where the electronic current flows are very robust. They persist independently of some external disturbances that one can have in experiments, such as weak disorder or temperature fluctuations, and they’re also independent of size. This is very interesting because it means these materials have a constant resistance, a constant conductivity. Having such tight control of the electronic current is useful for many applications.