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arXiv · 2007.11364

Fully gapped superconductivity without sign reversal in the topological superconductor PbTaSe$_2$

Yue Sun·Shunichiro Kittaka·Toshiro Sakakibara·Kazushige Machida·R. Sankar·Xiaofeng Xu·Nan Zhou·Xiangzhuo Xing·Zhixiang Shi·Sunseng Pyon·Tsuyoshi Tamegai
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Abstract

We investigate the superconducting gap function of topological superconductor PbTaSe$_2$. Temperature, magnetic field, and three-dimensional (3D) field-angle dependences of the specific heat prove that the superconductivity of PbTaSe$_2$ is fully-gapped, with two isotropic $s$-wave gaps. The pair-breaking effect is probed by systematically increasing non-magnetic disorders through H$^+$-irradiations. The superconducting transition temperature, $T_{\rm{c}}$, is found to be robust against disorders, which suggests that the pairing should be sign-preserved rather than sign-reversed.

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Yue Sun, Shunichiro Kittaka, Toshiro Sakakibara, Kazushige Machida, R. Sankar, Xiaofeng Xu, Nan Zhou, Xiangzhuo Xing, Zhixiang Shi, Sunseng Pyon, Tsuyoshi Tamegai. 2020-07-22. Fully gapped superconductivity without sign reversal in the topological superconductor PbTaSe$_2$. https://doi.org/10.1103/physrevb.102.024517

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