Unified Electrical and Sliding Control of the Spin–Valley–Layer Polarized Anomalous Hall Effect in Janus YFI Bilayers

Two-dimensional (2D) ferrovalley bilayers with coupled spin, valley, and layer degrees of freedom offer a promising platform for valleytronic applications. However, a unified understanding of how these properties can be controlled by external stimuli remains lacking. Here, we demonstrate a universal mechanism for electrically tuning valley splitting and the spin–valley–layer polarized anomalous Hall effect (AHE) in Janus YFI bilayers. We systematically examine how interlayer sliding and external electric fields modulate the band structure and valley polarization in 2H-YFI bilayers and construct a two-band k · p model to reveal the underlying physics. Interestingly, interlayer antiferromagnetic coupling and layer-asymmetric charge redistribution in YFI bilayers give rise to a spin–valley–layer polarized AHE. Both interlayer sliding and external electric fields effectively control the valley polarization and Hall response, showing functional equivalence in modulating these properties. Our work establishes a unified electrical control strategy for bilayer ferrovalley systems, facilitating the design of nonvolatile valleytronic devices.