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arXiv · 1310.8368

A Non-Centrosymmetric Superconductor with a Bulk 3D Dirac Cone Gapped by Strong Spin Orbit Coupling

Mazhar N. Ali·Quinn Gibson·Tomasz Klimczuk·R. J. Cava
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Abstract

Layered, non-centrosymmetric, heavy element PbTaSe2 is found to be superconducting. We report its electronic properties accompanied by electronic structure calculations. Specific heat, electrical resistivity and magnetic susceptibility measurements indicate that PbTaSe2 is a moderately coupled, type-II BCS superconductor (Tc = 3.72 K, Ginzburg-Landau parameter Kappa = 14) with an electronphonon coupling constant of Lambda_ep = 0.74. Electronic structure calculations reveal a single bulk 3D Dirac cone at the K point of the Brillouin Zone derived exclusively from its hexagonal Pb layer; it is similar to the feature found in graphene except there is a 0.8 eV gap opened by spin-orbit coupling. The combination of large spin-orbit coupling and lack of inversion symmetry also results in large Rashba splitting on the order of tenths of eV.

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Mazhar N. Ali, Quinn Gibson, Tomasz Klimczuk, R. J. Cava. 2013-10-31. A Non-Centrosymmetric Superconductor with a Bulk 3D Dirac Cone Gapped by Strong Spin Orbit Coupling. https://doi.org/10.1103/physrevb.89.020505

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