论文标题
直接观察不固定的电荷密度波调制中的准1D Weyl Semimetal候选NBTE $ _4 $
Direct observation of discommensurate charge density wave modulation in the quasi-1D Weyl semimetal candidate NbTe$_4$
论文作者
论文摘要
过渡金属四核苷元是一个模型系统，旨在探索相关电子状态（例如电荷密度波（CDW））与物质拓扑阶段的连接。了解这些阶段之间的联系需要对单个状态有透彻的了解，而对于本系统中的CDW，仍然缺少。在本文中，我们结合了声子结构计算和扫描隧道显微镜测量NBTE $ _4 $，以提供CDW状态的完整表征。我们发现，在短范围内，CDW形成的上层建筑与晶格参数完全相称。此外，我们的数据揭示了纳米级中相应CDW区域分离区域的相滑域壁的存在，这表明该化合物中的CDW在长期内是不均匀的。我们的结果解决了有关这些材料中CDW性质的长期讨论，并为研究该状态与其他新型量子电子状态之间的相互作用提供了强有力的基础。
The transition-metal tetrachalcogenides are a model system to explore the conjunction of correlated electronic states such as charge density waves (CDW), with topological phases of matter. Understanding the connection between these phases requires a thorough understanding of the individual states, which for the case of the CDW in this system, is still missing. In this paper we combine phonon-structure calculations and scanning tunneling microscopy measurements of NbTe$_4$ in order to provide a full characterization of the CDW state. We find that, at short range, the superstructure formed by the CDW is fully commensurate with the lattice parameters. Moreover, our data reveals the presence of phase-slip domain-walls separating regions of commensurate-CDW in the nanoscale, indicating that the CDW in this compound is discommensurate at long-range. Our results solve a long-standing discussion about the nature of the CDW in these materials, and provide a strong basis for the study of the interplay between this state and other novel quantum electronic states.
