Investigation of the room-temperature photoelectron spectroscopy of type-II Weyl semimetal candidate WTe2

• Published in: Tungsten 2023-09, Vol.5 (3), p.350-356
• Main Authors: Ding, Jian-Yang, Liu, Zheng-Tai, Huang, Zhe, Jiang, Zhi-Cheng, Yang, Yi-Chen, Liu, Zhong-Hao, Liu, Ji-Shan, Guo, Yan-Feng, Shen, Da-Wei
• Format: Article
• Language: English
• Subjects: Approximation; Chemical potential; Chemistry and Materials Science; Crystal structure; Electronic structure; Electrons; Energy bands; Fermi level; Fermi surfaces; Giant magnetoresistance; Low temperature; Magnetoresistivity; Materials Engineering; Materials Science; Metallic Materials; Nuclear Chemistry; Original Paper; Particle and Nuclear Physics; Phase transitions; Photoelectron spectroscopy; Photoelectrons; Physical properties; Room temperature; Single crystals; Spectrum analysis; Symmetry; Temperature; Transition metal compounds
• ISSN: 2661-8028; 2661-8036
• DOI: 10.1007/s42864-023-00209-1

Layered transition metal dichalcogenides have novel physical properties and great potential for applications. Among them, WTe 2 , which has an extremely large unsaturated magnetoresistance and is theoretically predicted to be a type-II Weyl semimetal, has been extensively studied. Here, we systematically probe the electronic structure of WTe 2 at room temperature using high-resolution angle-resolved photoelectron spectroscopy (ARPES). We find that temperature-driven chemical potential shift and Lifshitz transition, which is equivalent to low-energy band structures shift downward by around 50 meV, compared to the results at low temperatures. Our ARPES experimental results match well with previous theoretical calculations, implying the possible existence of type-II Weyl points near the Γ- X axis. Also, as expected, there exists a dominantly electron-like Fermi surface instead of the one with compensated electrons and holes. Meanwhile, our ARPES results show that the flat band (FB) lying below the Fermi level ( E F ) becomes closer to the Fermi level at room temperature, which might start to dominate the transport behavior and lead to the disappearance of the unsaturated giant magnetoresistance effect. These findings not only reveal the electronic structure features of WTe 2 at room temperature, but also provide new insights into the development of room-temperature topological quantum devices.