2023/10/09 by Zhen Zhang, Zhang, Zhen, Zhichao Zhou +9
Physics and Astronomy · Materials Science · #Topological Materials and Phenomena #Graphene research and applications #Quantum and electron transport phenomena
paper · pdf · doi:10.48550/arxiv.2310.05356
The quantum anomalous Hall state with a large band gap and a high Chern number is significant for practical applications in spintronics. By performing first-principles calculations, we investigate electronic properties of the fully fluorinated 1T-MoSe2 monolayer. Without considering the spin-orbit coupling, the band structure demonstrates single-spin semi-metallic properties and the trigonal warping around K± valleys. The introduction of the spin-orbit coupling opens considerable band gaps of 117.2 meV around the two valleys, leading to a nontrivial quantum anomalous Hall state with a Chern number of |C|=2, which provides two chiral dissipationless transport channels from topological edge states and associated quantized anomalous Hall conductivity. In addition, an effective model is constructed to describe the low-energy physics of the monolayer. Our findings in the MoSe2F2 monolayer sheds light on large-gap quantum anomalous Hall states in two-dimensional materials with the chemical functionalization, and provides opportunities in designing low-power and noise-tolerant spintronic devices.