Probing the location of Josephson vortices and the Majorana states bound to them in S-TI-S lateral Josephson junctions via Scanning SQUID Microscopy

Superconducting-Topological Insulator-Superconducting (S-TI-S) Josephson junctions are a promising platform for creating and manipulating Majorana bound states (MBS). The MBS are localized at the cores of Josephson vortices where the phase difference across the junction is an odd-multiple of π. They can be manipulated by applying fields and currents to carry out braiding operations for quantum information processing. To optimize braiding protocols, it is useful to track the motion of the vortices via local magnetic imaging. We are developing a Scanning SQUID Microscope in which the probe is a superconducting pickup loop with submicron dimensions. It is inductively-coupled to a commercial dc SQUID, providing the required field sensitivity and spatial resolution. In this talk, we report our progress towards imaging the Josephson vortices and the currents carried by the Majorana states.