Proximity-induced unconventional superconductivity in hybrid superconductor-topological insulator devices

Topological insulators in proximity to an s-wave superconductor or doped into a bulk superconducting state have been predicted to exhibit signatures of unconventional superconductivity. These system have been predicted to show signatures of a p-wave like superconducting order parameter, but the pairing symmetry has not been definitively confirmed by experiment. We will present ongoing work on Josephson interferometry measurements to probe the superconducting order parameter in Nb-Bi2Se3 interfaces and in NbxBi2Se3 crystals. We also investigate the transport properties in these materials by measuring local and non-local resistance using two and three terminal devices. We see signatures of a p-wave superconducting order parameter in the conductance of both systems and an unusual asymmetrical non local response that may result from the topological nature of the system.