Diamagnetic mechanism of non-reciprocal superconductivity in multilayered superconductors.

Non-reciprocal superconductivity has been a topic of great interest, motivated by the role of spin-orbit interactions on superconductor properties. Here we analyze critical current in a multilayer superconductor and show that formation of diamagnetic currents in the presence of magnetic field leads to non-reciprocity. This is a generic mechanism of non-reciprocity and should be present in all multilayered superconductors with interlayer spacing less than coherence length to preserve phase coherence between the layers. Above some critical current and magnetic field it is energetically favorable to form Josephson vortices, formation of vortices results in non-monotonic variation of non-reciprocal current contribution as a function of magnetic field and may result in its sign change. We report observation of non-reciprocal critical current in Al/InAs nanowires and show that magnetic field evolution of non-reciprocal critical current is consistent with the presence of diamagnetic currents and formation of Josephson vortices.