Robust quantum anomalous Hall effect in a pentagonal MoS2 monolayer grown on CuI(001) substrates

Recently, the square planar MoS2 monolayer, which exhibits the Cairo pentagonal tiling (termed as 1P-MoS2), was identified as an intrinsic quantum anomalous Hall (QAH) insulator. However, there is a paucity of theoretical work concerning a suitable substrate to support its nontrivial electron transport properties, which is the prerequisite for practical applications. Here. we demonstrate that CuI(001) serves an excellent substrate candidate for epitaxial growth of the 1P-MoS2 sheet by showing that the intrinsic ferromagnetism and the QAH state of 1P-MoS2 remain unaltered in the 1P-MoS2/CuI(001) system. Further analyses of the strain effect on 1P-MoS2 reveal that the QAH is robust within a strain range from - 2% to 2%. Our findings will inspire the experimental realization of QAH effects in two-dimensional (2D) pentagon-based materials.