Search for Majorana bound states in niobium-Bi2Se3-niobium arrays and junctions

Under the right conditions, Majorana bound states (MBS) are believed to live in lateral Josephson junctions formed by depositing s-wave superconductors onto the surface of topological insulator thin films, e.g., Bi2Se3.
We have fabricated and measured lateral superconductor-topological insulator-superconductor (S-TI-S) single junctions, square arrays, transmon geometries, and other geometries to look for the signatures of MBS.
Our experiments include Fraunhofer patterns on such patterns, which show some signature kinks at fields less then flux quantum, lifted nodes, and missing critical current maxima. We will discuss extensive measurement performed on niobium-Bi2Se3 hybrid structures in microwave resonators, which include kinetic inductance vs. magnetic field and the quality factor vs. magnetic field measurements. The possibility of making a transmon qubit with a topological insulator film will be discussed.