Superconductivity in topological insulators: From topological phase transition to Neutrino Oscillations.
The presence of helical surface states in topological insulators motivated many theoretical and experimental studies on the transport properties of such states. Unfortunately the bulk conducting bands have been shown to greatly challenge experimental observation of unique transport properties of the surface states, such as in absence of back scattering by non-magnetic impurities. In this talk I will show that in the presence of superconducting Cooper-paring, the signature of topological properties is apparent in the features of supercurrent transport through both surface and in the bulk of topological insulators. In particular by study of Josephson junctions made on the top of topological insulators, I will discuss the non-trivial temperature dependence of critical current as well as distribution of supercurrent in the junction which is controllable by external gating. I will show that puzzling recent experimental results are well consistent with our theoretical model of supercurrent transport in these materials and are indeed presenting signature of a topological phase transition in superconductor-topological insulator-superconductor Josephson junctions.
Phys. Rev. Lett. 116, 037001 (2016)
Phys. Rev. B 93, 035307 (2016)