M Pd5 kagome superconductors studied by density functional calculations

Kagome materials, which are composed of hexagons tiled with a shared triangle, have inspired enormous interest due to their unique structures and rich physical properties; exploring superconducting material systems with new kagome structures is still an important research direction. Here, we predict a type of kagome superconductor, MPd5 (M is a group-IIA metal element), and identify that it exhibits coexistence of superconductivity and nontrivial topological properties. We uncover its phonon-mediated superconductivity by the density functional theory for superconductors, predicting the superconducting transition temperatures (Tc) of 2.64, 2.03, and 1.50 K for CaPd5, SrPd5, and BaPd5, respectively. These Tc can be effectively tuned through the application of external pressure and electron doping. The present results also demonstrate that MPd5 have topological properties; e.g., CaPd5 shows topological nontrivial intersection near the Fermi level (EF). Our results indicate that MPd5 materials can be an emerging material platform with rich exotic physics in their kagome structures, and render themselves excellent candidates for superconducting and advanced functional materials that could be utilized in topological quantum computing and information technology.