Proximity induced superconductivity on the surface of nodal line Weyl semimetals

In this work we study the nature of the superconducting pairing induced by proximity on the surface of Weyl semimetals (WSM) with nodal lines in WSM-superconductor heterostructures. The surface of a nodal line WSM is characterized by the presence of topologically protected "drumhead'' surface states whose Fermi surfaces are the projection on the surface of the WSM nodal lines. We study how symmetry breaking terms that preserve the nodal line character of the WSM affect the symmetry of the induced superconducting pairing on the surface of the WSM and the effect of orbital-dependent tunneling. We then discuss the concrete case of a heterostructure formed by a nodal line WSM and an s-wave superconductor with Rashba spin-orbit coupling.