Multiple Dirac nodal lines in an in-plane anisotropic semimetal <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi mathvariant="normal">TaNiTe</mml:mi><mml:mn>5</mml:mn></mml:msub></mml:math>
Zhanyang Hao, Weizhao Chen, Yuan Wang, Jiayu Li, Xiao‐Ming Ma, Yu‐Jie Hao, Ruie Lu, Zecheng Shen, Zhicheng Jiang, Wan‐Ling Liu, Qi Jiang, Yichen Yang, Lei Xiao, Le Wang, Ying Fu, Liang Zhou, Lianglong Huang, Zhengtai Liu, Mao Ye, Dawei Shen, Jia‐Wei Mei, Hongtao He, Cai Liu, Ke Deng, Chang Liu, Qihang Liu, Kai Chen
Abstract
Nodal-line semimetals (NLSMs) contain Dirac-Weyl-type band-crossing nodes extending into shapes of lines, loops, and chains in the reciprocal space, leading to band topology and transport responses. Robust NLSMs against spin-orbit coupling typically occur in three-dimensional and in-plane isotropic materials which have more symmetry operations to protect the line nodes of band crossing, while the possibilities in exfoliatable materials with in-plane anisotropy are rarely discussed. Here, we demonstrate a robust NLSM phase in an exfoliatable in-plane anisotropic nonmagnetic semimetal $\mathrm{TaNi}{\mathrm{Te}}_{5}$. Combining angle-resolved photoemission spectroscopy measurements and first-principles calculations, we reveal multiple Dirac-type nodal lines with fourfold degeneracy in $\mathrm{TaNi}{\mathrm{Te}}_{5}$. Our findings suggest rich physics in structurally anisotropic topological materials and call for further functional exploitation based on them.