Multiple nodeless superconducting gaps in noncentrosymmetric superconductor PbTaSe2 with topological bulk nodal lines

M. X. Wang; Y. Xu; L. P. He; J. Zhang; X. C. Hong; P. L. Cai; Z. B. Wang; J. K. Dong; S. Y. Li

doi:10.1103/physrevb.93.020503

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arXiv · 1511.02730

Multiple nodeless superconducting gaps in noncentrosymmetric superconductor PbTaSe2 with topological bulk nodal lines

M. X. Wang·Y. Xu·L. P. He·J. Zhang·X. C. Hong·P. L. Cai·Z. B. Wang·J. K. Dong·S. Y. Li

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Abstract

Low-temperature thermal conductivity measurements were performed on single crystal of PbTaSe$_2$, a noncentrosymmetric superconductor with topological bulk nodal lines in the electronic band structure. It is found that the residual linear term $κ_0/T$ is negligible in zero magnetic field. Furthermore, the field dependence of $κ_0/T$ exhibits a clear "$S$"-shape curve. These results suggest that PbTaSe$_2$ has multiple nodeless superconducting gaps. Therefore, the spin-triplet state with gap nodes does not play an important role in this noncentrosymmetric superconductor with strong spin-orbital coupling. The fully gapped superconducting state also meets the requirement of a topological superconductor, if PbTaSe$_2$ is indeed the case.

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M. X. Wang, Y. Xu, L. P. He, J. Zhang, X. C. Hong, P. L. Cai, Z. B. Wang, J. K. Dong, S. Y. Li. 2015-11-09. Multiple nodeless superconducting gaps in noncentrosymmetric superconductor PbTaSe2 with topological bulk nodal lines. https://doi.org/10.1103/physrevb.93.020503

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