Angle-resolved photoemission spectroscopy study of charge density wave order in the layered semiconductor EuTe 4

作者：Chen Zhang, Qi-Yi Wu, Yahua Yuan, Xin Zhang, Hao Liu, Ziteng Liu, Hongyi Zhang, Jiaojiao Song, Yin-Zou Zhao, Fan-Ying Wu, Shu-Yu Liu, Bo Chen, Xue-Qing Ye, Shengtao Cui, Zhe Sun, Xiaofang Tang, Jun He, Haiyun Liu, Yu-Xia Duan, Yanfeng Guo, Jian-Qiao Meng · 发表于：Physical review. B./Physical review. B · 年份：2022 · DOI：10.1103/physrevb.106.l201108 · 被引用次数：17 · 研究领域：Organic and Molecular Conductors Research、2D Materials and Applications、Iron-based superconductors research

Layered tellurides have been extensively studied as a platform for investigating the Fermi surface (FS) nesting-driven charge density wave (CDW) states. ${\mathrm{EuTe}}_{4}$, one of the quasi-two-dimensional binary rare-earth tetratelluride CDW compounds with unconventional hysteretic transition, is currently receiving much attention. Here, the CDW modulation vector, momentum, and temperature dependence of CDW gaps in ${\mathrm{EuTe}}_{4}$ are investigated using angle-resolved photoemission spectroscopy. Our results reveal that (i) a FS nesting vector $\mathit{q}\ensuremath{\approx}0.67{\mathbit{b}}^{*}$ drives the formation of the CDW state, (ii) a large anisotropic CDW gap is fully open in the whole FS and maintains a considerable size even at 300 K, leading to the appearance of semiconductor properties, (iii) an abnormal behavior of CDW gap in magnitude as a function of temperature, and (iv) an extra, larger gap opens at higher binding energy due to the interaction between the different orbits of the main bands.