CaPtAs: A new noncentrosymmetric superconductor  

作　　者：Wu Xie PeiRan Zhang Bin Shen WenBing Jiang GuiMing Pang Tian Shang Chao Cao Michael Smidman HuiQiu Yuan 

机构地区：[1]Center for Correlated Matter and Department of Physics,Zhejiang University,Hangzhou 310058,China [2]Physik-Institut,Universitat Zürich,Zurich CH-8057,Switzerland [3]Department of Physics,Hangzhou Normal University,Hangzhou 310036,China [4]Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2020年第3期98-105,共8页中国科学：物理学、力学、天文学（英文版）

基　　金：the National Key R&D Program of China(Grant Nos.2016YFA0300202,and 2017YFA0303100);the National Natural Science Foundation of China(Grant Nos.U1632275,and 11874320);the Science Challenge Project of China(Grant No.TZ2016004);the Fundamental Research Funds for the Central Universities.

摘　　要：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 fieldμ0Hc2 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.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.

关 键 词：NONCENTROSYMMETRIC SUPERCONDUCTIVITY CaPtAs 

分 类 号：TM26[一般工业技术—材料科学与工程]