By Andrew Grant
Throw some electrons onto the surface of a topological insulator and they seemingly become invincible, effortlessly bypassing obstructions along their route. Now researchers have crafted a structure that empowers particles of light to do the same thing. The first demonstration of a topological insulator for photons, reported April 10 in Nature, could lead to improved optical transmissions that are crucial for global communication.
“I think it’s wonderful,” says Michal Lipson, a physicist at Cornell University who was not involved with the study. “The light goes right around any obstacles, which is pretty remarkable.”
Topological insulators have been a burgeoning area of condensed-matter physics since they were proposed in 2005 (SN: 5/22/10, p. 22). Typical materials are either conductors or insulators, but topological insulators such as bismuth telluride are exotic hybrids: They block electric current yet allow electrons to flow along their surfaces.
What’s more, these surface electrons can move unimpeded through bumps and grooves that would normally block their path. That useful property makes topological insulators intriguing candidates for future electronics.