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arXiv · 2004.03441

Anisotropic gapping of topological Weyl rings in the charge-density-wave superconductor InxTaSe2

Yupeng Li·Yi Wu·Chenchao Xu·Ningning Liu·Jiang Ma·Baijiang Lv·Gang Yao·Yan Liu·Hua Bai·Xiaohui Yang·Lei Qiao·Miaocong Li·Linjun Li·Hui Xing·Yaobo Huang·Junzhang Ma·Ming Shi·Chao Cao·Yang Liu·Canhua Liu·Jinfeng Jia·Zhu-An Xu
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Abstract

Topological materials and topological phases have recently become a hot topic in condensed matter physics. In this work, we report a topological nodal-line semimetal InxTaSe2, in the presence of both charge density wave (CDW) and superconductivity. In the x = 0.58 samples, the 2 * /3 commensurate CDW (CCDW) and the 2 * 2 CCDW are observed below 116 K and 77 K, respectively. Consistent with theoretical calculations, the spin-orbital coupling gives rise to two two-fold-degenerate nodal rings (Weyl rings) connected by drumhead surface states, confirmed by angle-resolved photoemission spectroscopy. Our results suggest that the 2 * 2 CCDW ordering gaps out one Weyl ring in accordance with the CDW band folding, while the other Weyl ring remains gapless with intact surface states. In addition, superconductivity emerges at 0.91 K, with the upper critical field deviating from the s-wave behavior at low temperature, implying possibly unconventional superconductivity. Therefore, InxTaSe2 represents an interesting material system to study the interplay between CDW, nontrivial band topology and superconductivity.

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Yupeng Li, Yi Wu, Chenchao Xu, Ningning Liu, Jiang Ma, Baijiang Lv, Gang Yao, Yan Liu, Hua Bai, Xiaohui Yang, Lei Qiao, Miaocong Li, Linjun Li, Hui Xing, Yaobo Huang, Junzhang Ma, Ming Shi, Chao Cao, Yang Liu, Canhua Liu, Jinfeng Jia, Zhu-An Xu. 2020-04-07. Anisotropic gapping of topological Weyl rings in the charge-density-wave superconductor InxTaSe2. https://doi.org/10.1016/j.scib.2020.09.007

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