Exploring signatures of Majorana modes in the current-phase relation of S-TI-S Josephson junctions

Majorana bound states (MBS) have been explored as an approach to realizing topologically-protected quantum computing in condensed matter systems. Exhibited in Superconductor-Topological Insulator-Superconductor (S-TI-S) lateral Josephson junctions, it is predicted that MBS are nucleated at the cores of Josephson vortices where the phase difference across the junction is an odd multiple of π. We study the current-phase relation of these junctions, in which a contribution with a 4π-periodic dependence is added due to the presence of MBS. We present experiments designed to probe the current-phase relation of the S-TI-S junction with direct measurements via phase-sensitive Josephson interferometry using a SQUID circuit, and indirectly by transport measurements of the magnetic field dependence of the critical current in asymmetric SQUIDs and Corbino disk junction geometries.