Topological Superconductivity in Crystalline Anisotropic Josephson Junctions

We theoretically investigate the emergence of Topological Superconductivity (TS) in planar JJs [1,2] subject to Rashba and Dresselhaus spin-orbit couplings (SOCs) and in-plane magnetic field. We focus on studying the effects of the junction crystallographic orientation and magnetic field direction on the capability for the system to enter TS and produce a significant topological gap for Majorana bound state (MBS) protection. The ability to electrically tune the topological phase, as well as transitions between BDI and D symmetry classes, has been found to greatly depend on the interplay between SOC strengths, magnetic field and crystallographic orientations [3]. Our findings provide guidelines for optimizing the topological gap protecting MBS in crystalline anisotropic planar JJs, especially in non-collinear junctions [4].

[1] A. Fornieri et al., Nature 569, 89 (2019); H. Ren et al., Nature 569, 93 (2019).
[2] W. Mayer et al., arXiv:190601179 (2019).
[3] J. D. Pakizer and A. Matos-Abiague, arXiv:2007.03498 (2020).
[4] T. Zhou et al., Phys. Rev. Lett. 124, 137001 (2020).