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

Abstract

Recently, the square planar ${\mathrm{MoS}}_{2}$ monolayer, which exhibits the Cairo pentagonal tiling (termed as $1\mathrm{P}\text{\ensuremath{-}}{\mathrm{MoS}}_{2}$), 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 $1\mathrm{P}\text{\ensuremath{-}}{\mathrm{MoS}}_{2}$ sheet by showing that the intrinsic ferromagnetism and the QAH state of $1\mathrm{P}\text{\ensuremath{-}}{\mathrm{MoS}}_{2}$ remain unaltered in the $1\mathrm{P}\text{\ensuremath{-}}{\mathrm{MoS}}_{2}$/CuI(001) system. Further analyses of the strain effect on $1\mathrm{P}\text{\ensuremath{-}}{\mathrm{MoS}}_{2}$ reveal that the QAH is robust within a strain range from $\ensuremath{-}$ 2% to 2%. Our findings will inspire the experimental realization of QAH effects in two-dimensional (2D) pentagon-based materials.