Superconductivity in Kagome Metal YRu_3Si_2 with Strong Electron Correlations

We report the detailed physical properties of YRu_3Si_2 with the Ru kagome lattice at normal and superconducting states. The results of resistivity and magnetization show that YRu_3Si_2 is a type-II bulk superconductor with T_\rm c\sim 3.0 K. The specific heat measurement further suggests that this superconductivity could originate from the weak or moderate electron-phonon coupling. On the other hand, both large Kadawaki–Woods ratio and Wilson ratio indicate that there is a strong electron correlation effect in this system, which may have a connection with the featured flat band of kagome lattice.