Charge order induced Dirac pockets in the nonsymmorphic crystal TaTe4
Charge order induced Dirac pockets in the nonsymmorphic crystal TaTe4
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DOI：
10.1103/physrevb.108.155121
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发表时间：
2023-04
影响因子：
3.7
通讯作者：
Yichen Zhang;Ruixiang Zhou;Hanlin Wu;J. Oh;Sheng Li;Jianwei Huang;J. Denlinger;M. Hashimoto
中科院分区：
文献类型：
--
作者：
Yichen Zhang;Ruixiang Zhou;Hanlin Wu;J. Oh;Sheng Li;Jianwei Huang;J. Denlinger;M. Hashimoto
电荷有序(CO)和非平凡能带拓扑之间的相互作用激发了人们对理解超越单粒子描述的拓扑激发的极大兴趣。在准一维非对称晶体Tate$_4$中，(2a$×$2b$\×$3c)电荷有序基态使系统进入一个空间群，在该空间群中对称性指示符以Dirac费米子和非传统的双Dirac费米子的出现为特征。利用角度分辨光电子能谱和第一性原理计算，我们提供了在费米能级附近CO诱导的Dirac费米子相关带的证据。此外，在费米能级的能带折叠与CO规定的新周期是相容的，这表明费米能级附近的电子遵循该系统中容纳双狄拉克费米子所需的晶体对称性。
The interplay between charge order (CO) and nontrivial band topology has spurred tremendous interest in understanding topological excitations beyond the single-particle description. In a quasi-one-dimensional nonsymmorphic crystal TaTe$_4$, the (2a$\times$2b$\times$3c) charge ordered ground state drives the system into a space group where the symmetry indicator features the emergence of Dirac fermions and unconventional double Dirac fermions. Using angle-resolved photoemission spectroscopy and first-principles calculations, we provide evidence of the CO induced Dirac fermion-related bands near the Fermi level. Furthermore, the band folding at the Fermi level is compatible with the new periodicity dictated by the CO, indicating that the electrons near the Fermi level follow the crystalline symmetries needed to host double Dirac fermions in this system.