Li Yunlong, Ran Zhao, Huang Chaozhi, Wang Guanyong, Shen Peiyue, Huang Haili, Xu Chunqiang, Liu Yi, Jiao Wenhe, Jiang Wenxiang, Hu Jiayuan, Zhu Gucheng, Xu Chenhang, Lu Qi, Wang Guohua, Jing Qiang, Wang Shiyong, Shi Zhiwen, Jia Jinfeng, Xu Xiaofeng, Zhang Wentao, Luo Weidong, Qian Dong
Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Phys Rev Lett. 2022 Mar 11;128(10):106802. doi: 10.1103/PhysRevLett.128.106802.
By combining angle-resolved photoemission spectroscopy, scanning tunneling microscopy, atomic force microscope based piezoresponse force microscopy and first-principles calculations, we have studied the low-energy band structure, atomic structure, and charge polarization on the surface of a topological semimetal candidate TaNiTe_{5}. Dirac-like surface states were observed on the (010) surface by angle-resolved photoemission spectroscopy, consistent with the first-principles calculations. On the other hand, piezoresponse force microscopy reveals a switchable ferroelectriclike polarization on the same surface. We propose that the noncentrosymmetric surface relaxation observed by scanning tunneling microscopy could be the origin of the observed ferroelectriclike state in this novel material. Our findings provide a new platform with the coexistence of a ferroelectriclike surface charge distribution and novel surface states.
通过结合角分辨光电子能谱、扫描隧道显微镜、基于原子力显微镜的压电力显微镜以及第一性原理计算，我们研究了拓扑半金属候选材料TaNiTe₅表面的低能能带结构、原子结构和电荷极化。角分辨光电子能谱在(010)表面观察到了类狄拉克表面态，这与第一性原理计算结果一致。另一方面，压电力显微镜揭示了同一表面上可切换的类铁电极化。我们提出，扫描隧道显微镜观察到的非中心对称表面弛豫可能是这种新型材料中观察到的类铁电态的起源。我们的发现提供了一个具有类铁电表面电荷分布和新型表面态共存的新平台。
