Dimension-dependent magnetic anisotropy for tunable anomalous Hall effectin transition metal dichalcogenides br

Two-dimensional (2D) ferromagnetism at room temperature is highly desired in spintronic devices and appli-cations. Recently, CrTe2film has been successfully synthesized. Bulk CrTe2has in-plane magnetic anisotropy(MA), and the Curie temperature reaches up to 300 K. When the dimensions are down to two, MA switchesto out-of-plane. However, the mechanism of MA transition from in-plane to out-of-plane remains unknown.Here, we investigate the switching of MA in CrTe2by second-order perturbation theory. The MA energy (MAE)originates from competition betweenpz/pyandpx/pyorbital hybridization, which contributes to out-of-planeand in-plane MA, respectively. Thepx/pyorbital hybridization, induced by van der Waals force, is absent inthe monolayer. Moreover, the out-of-plane MA of monolayer CrTe2breaks mirror symmetry, producing ananomalous Hall effect. Slight charge doping is significant to achieve a tunable anomalous Hall effect. Basedon charge doping, we design a spintronic anomalous Hall device by taking advantage of the easily controllableproperties of CrTe2. This highly thickness-dependent magnetism provides a perspective to control the magneticproperties of 2D materials