Intrinsic valley polarization and anomalous valley Hall effect in monolayer H-ScAt2

Materials with spontaneous polarization is very promising in valley electronics because of its potential application in encoding and storing information. In this paper, we proposed a stable two-dimensional ferromagnetic valley material $H$-ScAt${}_2$ which can spontaneously generate valley splitting and exhibit intrinsic anomalous Hall effect. The valley polarization is 0.245 eV, which is large than most of the reported materials. The structural stability is verified by our phonon and molecular dynamic calculation. The Curie temperature of $H$-ScAt${}_2$ monolayer is about 840 K, which is above room temperature.