Proximity Effect Induced Topological Superconductivity in CeBi Thin Films

Recently increasing evidence shows that magnetic CeBi can be a Weyl semimetal. With only one pair of Weyl nodes at low energies, CeBi serves as an interesting quantum material system to study various Weyl physics. In this work, we explore the possible emergence of topological superconductivity by sandwiching a CeBi thin film between two conventional superconductors like Niobium. After applying a magnetic field, CeBi can be in an antiferromagnetic, ferrimagnetic or ferromagnetic phase, which is coupled with the superconductors. We construct an accurate tight-binding multi-orbital Hamiltonian for CeBi from the first-principle electronic structure calculations. This enables us to get material-specific predictions on topological superconductivity. We obtain massless quasiparticle bands, which are chiral Majorana modes, when the CeBi is in the ferromagnetic phase. We anticipate that our theoretical results will provide a new platform of topological superconductivity arising from the Weyl materials, which is accessible to experimental observation.