Electric-field-induced quantum anomalous valley Hall effect in antiferromagnetic bilayer

The quantum anomalous valley Hall effect (QAVHE), the quantized counterpart of the anomalous valley Hall effect, holds significance in the fields of valleytronics and topotronics. Previous studies have demonstrated that the QAVHE can be realized through band inversion at one K valley in ferrovalley monolayers with hexagonal lattices using methods such as strain, magnetic fields, or tuning on-site repulsion energy. However, a more convenient approach—namely, the application of an electric field—has not been proposed to achieve the QAVHE. In this work, by leveraging the layer-spin-valley locking effect in an antiferromagnetic bilayer valley system, we predict that an electric field can induce valley polarization in such systems, ultimately enabling the realization of the QAVHE. Using k·p modeling and first-principles calculations, we elucidate the mechanism behind the electric-field-induced QAVHE and analyze the associated changes in optical absorption and magnetoelectric coupling. Our findings advance the understanding of the QAVHE and open pathways toward its practical applications.