Determining finite contact size corrections in the transport characterization of topological insulators

We investigate the effect that finite size contacts have on the surface and bulk conductivity of topological insulators. Determining the contribution is non-trivial without first knowing the conductivity of the material, which requires knowing the effect the contacts have. In this work we systematically study Hall transport in an ideal topological insulator with contacts of varying sizes and using finite element analysis. We present how the correction factors associated with contacts evolve with the size of the contacts, the sample thickness, and the relative contributions of bulk and surface conduction in an ideal topological insulator.