An experimental hunt for the surface states of a 3D topological insulator
Nicholas P. Butch
Center for Nanophysics and Advanced Materials, Department of Physics
Three dimensional topological insulators are bulk insulators with metallic surfaces that have a Dirac-like dispersion and spin chirality. The existence of these states is topologically protected, i.e., they are robust against disorder, and as such they are expected to be good conductors. Experimental signatures of these states have been widely reported, but primarily come from surface measurements.
contrast, the surface states are much more difficult to probe via bulk
electrical transport measurements. In reality, the materials that are called
topological insulators are metals and the bulk conduction masks that of the
surface. At the