Layer-polarized anomalous Hall effects in valleytronic van der Waals bilayers

The layer-polarized anomalous Hall effect (LP-AHE), derived from the coupling between the Berry curvature and the layer degree of freedom, is of importance for both fundamental physics and device applications. Nonetheless, the current research paradigm is rooted in topological systems, rendering such a phenomenon rather scarce. Here, through model analysis, we propose an alternative, but general, mechanism for realizing the LP-AHE in valleytronic van der Waals bilayers by interlayer sliding. The interaction between out-of-plane ferroelectricity and A-type antiferromagnetism gives rise to the layer-locked Berry curvature and thus the long-sought LP-AHE in bilayer systems. The LP-AHE can be strongly coupled with sliding ferroelectricity, rendering it ferroelectrically controllable and reversible. The mechanism is demonstrated in a series of real valleytronic materials, including bilayer VSi2P4, VSi2N4, FeCl2, RuBr2 and VClBr. The new mechanism and phenomena provide a significant new direction to realize the LP-AHE and explore its application in electronics.

Automated summary

By interlayer sliding, the layer-polarized anomalous Hall effect (LP-AHE) is achieved in valleytronic van der Waals bilayers. The LP-AHE can be strongly coupled with sliding ferroelectricity, making it ferroelectrically controllable and reversible. This new mechanism provides a significant direction for realizing the LP-AHE and exploring its application in electronics.