Weyl Fermions in VI3 Monolayer

• Main Authors: Taoyuan Jia, Weizhen Meng, Haopeng Zhang, Chunhai Liu, Xuefang Dai, Xiaoming Zhang, Guodong Liu
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2020-08-01
• Series: Frontiers in Chemistry
• Subjects: topological semimetal; 2D materials; first-principles calculations; half-metal; Weyl state
• Online Access: https://www.frontiersin.org/article/10.3389/fchem.2020.00722/full

We report the presence of a Weyl fermion in VI3 monolayer. The material shows a sandwich-like hexagonal structure and stable phonon spectrum. It has a half-metal band structure, where only the bands in one spin channel cross the Fermi level. There are three pairs of Weyl points slightly below the Fermi level in spin-up channel. The Weyl points show a clean band structure and are characterized by clear Fermi arcs edge state. The effects of spin-orbit coupling, electron correlation, and lattice strain on the electronic band structure were investigated. We find that the half-metallicity and Weyl points are robust against these perturbations. Our work suggests VI3 monolayer is an excellent Weyl half-metal.