Bound State Signatures in a Mesoscopic TI Josephson Junction

The engineering of hybrid Josephson junctions has increasingly become a key source in the experimental access to topological superconductivity, as these allow a high degree of robustness and control of their characteristic excitations. Here we consider a device where a topological insulator nanowire of type Bi2Se3 is proximitized to an isolated mesoscopic Josephson junction. Threaded with magnetic flux, the nanowire nucleates two pairs of topologically protected Majorana fermions as well as Andreev bound states in the weak-link. We investigate processes of coherent charge transfer mediated by these low-energy bound states in a mesoscopic setting, and show that they have a notable effect on the fermionic parity of the superconductors, as is evident in the response of the system to electromagnetic radiation.