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 = 4.18Å, and c = 43.70Å). 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 relatively large 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-5d and As-4p 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. PACS number(s):

No abstract