Anisotropic superconductivity in topological crystalline metal Pb${}_{1/3}$TaS${}_2$ with multiple Dirac fermions

Abstract

Topological crystalline metals/semimetals (TCMs) have stimulated a great research interest, which broaden the classification of topological phases and provide a valuable platform to explore topological superconductivity. Here, we report the discovery of superconductivity and topological features in Pb-intercalated transition-metal dichalcogenide Pb${}_{1/3}$TaS${}_2$. Systematic measurements indicate that Pb${}_{1/3}$TaS${}_2$ is a quasi-two-dimensional (q-2D) type-II superconductor ({\em T}${}_c\approx$ 2.8 K) with a significantly enhanced anisotropy of upper critical field (${\gamma }_{H_{c2}}$ = $H_{c2}^{ab}/H_{c2}^c$ $\approx$ 17). In addition, first-principles calculations reveal that Pb${}_{1/3}$TaS${}_2$ 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/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 Pb${}_{1/3}$TaS${}_2$ is a promising arena to study the interplay between superconductivity and topological Dirac fermions.

References in corpus (7)

• Topological Semimetals
• Limits of the upper critical field in dirty two-gap superconductors
• Dirac Line-nodes and Effect of Spin-orbit Coupling in Non-symmorphic Critical Semimetal MSiS (M=Hf, Zr)
• Nonsymmorphic-symmetry-protected hourglass Dirac loop, nodal line, and Dirac point in bulk and monolayer $X_3$SiTe${}_6$ ($X=$ Ta, Nb)
• Emergence of Topological Nodal Lines and Type II Weyl Nodes in Strong Spin--Orbit Coupling System InNbX2(X=S,Se)
• Superconducting and Topological Properties in Centrosymmetric PbTaS2 Single Crystals
• Enhanced anisotropic superconductivity in the topological nodal-line semimetal InxTaS2

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• Commensurate stacking phase transitions in an intercalated transition metal dichalcogenide
• Pressure-induced superconductivity reentrant in transition metal dichalcogenide TiSe2
• Growth and hydrostatic-pressure study of a type-II superconductor Bi${}_2$Ta${}_3$S${}_6$ single crystal
• Breaking the Trade-off: Bulk 2D Ising Superconductivity with High Tc and Giant Interlayer Spacing via a Unique Chain Intercalation in (BaS)1/3TaS2