Modelling the effect of Andreev bound states on quantum transport in superconducting magnetic topological systems

The quantum transport in the sub-gap regime (ΙEΙ ≤ ΙΔ0Ι) in magnetic-superconducting-topological heterostructures was modelled using the Bogoliubov-de Gennes equations in combination with the recurrence relations. Following the prediction by Fu and Kane [1], an interface between a magnetic- and (s-wave) superconducting topological insulator was shown to host chiral Majorana modes in the form of Andreev bound states. Zero-energy Majorana modes are a fruitful approach to fault-tolerant topological quantum computing [2]. A novel mechanism to invert the chirality of the Majorana modes in such systems is proposed. To study the effect of the Andreev bound states on the electrical transport properties, the multiple Andreev reflection spectra in a topological Josephson junction consisting of a magnetic tunnel barrier are computed using the recurrence relations. A relationship between the location of resonance peaks in the computed I; V -curves for the topological Josephson junction and the Andreev bound state energies is established.