| Abstract: | We report the discovery of a new noncentrosymmetric superconductor CaPtAs. It crystallizes in a tetragonal structure（space group I41md, No. 109）, featuring three dimensional honeycomb networks of Pt-As and a much elongated c-axis（a = b = 4.18 ?,and c = 43.70 ?）. The superconductivity of CaPtAs with Tc= 1.47 K was characterized by means of electrical resistivity, specific heat, and ac magnetic susceptibility. The electronic specific heat Ce（T）/T shows evidence for a deviation from the behavior of a conventional BCS superconductor, and can be reasonably fitted by a p-wave model. The upper critical field μ0Hc2 of CaPtAs exhibits a moderate anisotropy, with an in-plane value of around 204 mT and an out-of-plane value of 148 mT. Density functional theory calculations indicate that the Pt-5 d and As-4 p orbitals mainly contribute to the density of states near the Fermi level,showing that the Pt-As honeycomb networks may significantly influence the superconducting properties. |
