Switchable anomalous valley Hall effect in 2D antiferromagnetic system

Currently, the realization and control of anomalous valley Hall effect (AVHE) in two-dimensional antiferromagnetic (AFM) systems are predominantly achieved through optical excitation, which hinders its practical applications. Here, we propose a strategy to overcome this limitation by inserting a valley-active AFM layer between two ferromagnetic (FM) semiconductor layers. Using $\mathrm{Cr}{\mathrm{Cl}}_{3}\ensuremath{-}\mathrm{VSi}{\mathrm{S}}_{3}\ensuremath{-}\mathrm{Cr}{\mathrm{Cl}}_{3}$ heterotrilayer as a model system, our first-principles calculations reveal that interfacial proximity coupling can introduce intrinsic sublattice-asymmetric exchange field. This field can break the $\mathit{PT}$ symmetry and lift the spin degeneracy of valleys in the AFM layer while preserving its intrinsic valley polarization, thereby inducing a pronounced AVHE. Crucially, the sublattice-asymmetric exchange field can be reversed through flipping the magnetization orientation of the FM layers, resulting in reversible static control of AVHE without altering the AFM N\'eel order. These findings establish an alternative paradigm for controlling AVHE in AFM materials and advance the field of antiferromagnet-based valleytronics.