Superconducting properties and topological nodal lines features in centrosymmetric Sn_0.5TaSe₂

Nontrivial topological behaviors in superconducting materials provide resourceful ground for the emergence and study of unconventional quantum states. Charge doping by the controlled intercalation of donor atoms is an efficient route for enhancing/inducement of superconducting and topological behaviors in layered topological insulators and semimetals. Herein, we enhanced the superconducting temperature of TaSe₂ by 20-folds (~ 3 k) through Sn atoms intercalation. Using first-principles calculations, we demonstrated the existence of nontrivial topological features. Sn_0.5TaSe₂ displays topological nodal lines around the K high symmetry point in the Brillouin zone, with drumhead-like shaped surface states protected by inversion symmetry. Altogether, the coexistence of these properties makes Sn_0.5TaSe₂ a potential candidate for topological superconductivity.