Anisotropic superconductivity in the topological crystalline metal Pb1/3TaS2 with multiple Dirac fermions

Article

关键词: BAND-STRUCTURE CALCULATIONS;    UPPER CRITICAL-FIELD;    SCHEMES;   

DOI  :  10.1103/PhysRevB.104.035157

来源: SCIE

【 摘 要 】

Topological crystalline metals and semimetals (TCMs) have stimulated great research interest, which broadens the classification of topological phases and provides a valuable platform to explore topological superconductivity. Here, we report the discovery of superconductivity and topological features in Pb-intercalated transition-metal dichalcogenide Pb1/3TaS2. Systematic measurements indicate that Pb1/3TaS2 is a quasi-two-dimensional (q-2D) type-II superconductor (T-c approximate to 2.8 K) with a significantly enhanced anisotropy of upper critical field (gamma H-c2 = H-c2(ab) / H-c2(c) approximate to 17). In addition, first-principles calculations reveal that Pb1/3TaS2 hosts multiple topological Dirac fermions in the electronic band structure. We discover four groups of Dirac nodal lines on the k(z) = pi plane and two sets of Dirac points on the rotation or screw axes, which are protected by crystalline symmetries and robust against spin-orbit coupling (SOC). Dirac-cone-like surface states emerge on the (001) surface because of band inversion. Our work shows that the TCM candidate Pb1/3TaS2 is a promising arena to study the interplay between superconductivity and topological Dirac fermions.

【 授权许可】

Free