Topological insulator plasmonics

Topological insulators (TIs) are a new type of material that has recently been discovered. They have highly conductive surface states, while their bulk remains insulating. Because of extremely strong spin-orbit coupling in these materials, surface electrons have a spin-momentum locking texture, so that they are almost free from scattering, known as topological protection. The electrons are also massless Dirac particles similar to those in graphene, even at room temperature.

While most work to-date has been focused on the use of TIs in electronic devices, there have recently been exciting theoretical proposals of how this new type of material interacts with light. These have predicted exotic light-matter interactions between the surface electrons in the TI and photons. Because the topologically protected carriers are confined to the surface of the material, by controlling the physical shape of the material on the nanometer scale the material interaction with light can be controlled. These interactions represent a new type of light-matter phenomena and could lead to applications in sensor technology, optical coatings and new laser technologies.