Topological insulators (TI’s) are materials that are insulators in their interiors, but have unique conducting states on their surfaces. They have attracted significant interest as fundamentally new electronic phases having potential applications from dissipationless interconnects to quantum computing. In this talk, I will discuss transport measurements of the topological surface state of the 3D TI Bi2Se3. I will describe several measurements which demonstrate the unique properties of surface transport: TI-superconductor junctions where the supercurrent is flows primarily through surface states, Aharonov-Bohm effects which demonstrate ballistic surface transport, and Fraunhofer spectroscopy where an in-plane magnetic field leads to finite momentum shifts in Cooper pairs.
