Ferroelectric control of the layer-polarized anomalous Hall effect in a 2D TiClAsH bilayer via superposition engineering

Ferrovalley (FV) materials have attracted much attention due to their unique spin-valley coupled properties. In this work, we predict FV single-layer TiClAsH, which has 77 meV of intrinsic valley polarization. The electronic correlation effect can drive the topological phase transition from the FV state to the quantum anomalous Hall state, and its critical half-valley metallic phase can achieve complete spin polarization. By breaking the mirror symmetry of bilayer TiClAsH, the layer-locked Berry curvature distribution is achieved, and furthermore, the layer-polarized anomalous Hall effect (LPAHE) is induced. Meanwhile, reversible LPAHE switching can be achieved through sliding control of ferroelectricity. Our findings offer a good material platform to manipulate the spin splitting, valley polarization, ferroelectricity, and topological states for multi-functional device applications.