Controllable topological superconductivity in superconductor/ferromagnet heterostructures.

Majorana zero modes emerge at the defects of topological p-wave superconductors. However since p-wave superconductivity is scarce in nature several proposals have been put forward to engineer Majorana zero modes using conventional superconductors. Our group proposes a novel platform for topological superconductivity and Majorana zero modes comprising conventional superconductor (SC)/ ferromagnet (F) heterostructures. Our mechanism relies on the interplay of applied supercurrents (blue arrows) and weak magnetic fields (black arrows) emerging from the magnetic insulators (MI) in proximity with the conventional superconductors. We demonstrate that the coexistence of the supercurrent, the weak magnetic field and conventional superconductivity induces triplet p-wave correlations which mediate in the ferromagnet, whose magnetization is indicated by the white arrow, realizing an effectively spinless topological superconductor. We assert that the proposed superconductor/ferromagnet heterostructures exhibit enhanced controllability since topological superconductivity can be tuned apart from gate voltages applied on the superconductor or the ferromagnet, also by the applied supercurrents and the orientation of the magnetization of the magnetic insulators.