Experimental and first-principles studies of superconductivity in topological nodal line semimetal SnTaS$_2$

Abstract

We report a detailed study of superconductivity in polycrystalline SnTaS2 using electrical transport, magnetization and heat capacity measurements. SnTaS2 crystallizes in centrosymmetric hexagonal structure with space group P 63/mmc. Electrical resistivity, magnetization and specific heat data suggest SnTaS2 to be a weakly coupled, type-II superconductor with Tc ≈ 2.8 K. Firstprinciples calculations show signature for nodal line topology, protected by the spatial-inversion and time-reversal symmetries, that strongly gapped out by the inclusion of spin-orbit coupling (SOC). Superconductivity in layered SnTaS2 with nodal line topological state makes it a strong candidate to be considered for a 3D topological superconductor.