STM Probe of the Superconductor/Topological Insulator Interface

Interfacing a 3D topological insulator with a superconductor has been shown to induce superconductivity into the topological insulator material. In this talk, we will present cryogenic scanning tunneling microscopy measurements done on epitaxially grown Bi2Se3 with various thicknesses of superconducting Nb films deposited on top. In this system, we see indications of the topologically-protected surface states leaking into the superconductor -- evidence for the existence of an inverse topological proximity effect (ITPE). Specifically, both the superconducting energy gap feature and the Dirac cone are superposed in the electronic density of states. Theoretical modeling of the ITPE will be presented.