Zusammenfassung
Topological insulator (TI) nanowires in proximity to conventional superconductors have been proposed as a
tunable platform to realize topological superconductivity and Majorana zero modes. The tuning is done using
an axial magnetic flux φ which allows transforming the system from trivial at φ = 0 to topologically nontrivial
when half a magnetic flux quantum φ_0/2 threads the cross-section of ...
Zusammenfassung
Topological insulator (TI) nanowires in proximity to conventional superconductors have been proposed as a
tunable platform to realize topological superconductivity and Majorana zero modes. The tuning is done using
an axial magnetic flux φ which allows transforming the system from trivial at φ = 0 to topologically nontrivial
when half a magnetic flux quantum φ_0/2 threads the cross-section of the wire. Here, we explore the expected
topological transition in TI-wire-based Josephson junctions as a function of magnetic flux by probing the 4π-periodic fraction of the supercurrent, which is considered an indicator of topological superconductivity. Our data
suggest that this 4π-periodic supercurrent is at lower magnetic field largely of trivial origin but that, at magnetic
fields above ∼φ_0/4, topological 4π-periodic supercurrents take over.