Tailoring the quantum anomalous layer Hall effect in multiferroic bilayers through sliding

Layer Hall effect (LHE) initially discovered in the magnetic topological insulator MnBi₂Te₄ film expands the Hall effect family and opens a promising avenue for layertronics applications. In this study, we present an innovative ferroelectric bilayer model to attain a tunable quantum anomalous layer Hall effect (QALHE). This model comprises two ferromagnetic orbital-active Dirac monolayers stacked antiferromagnetically, accompanied by out-of-plane electric polarization. The interplay between the layer-locked Berry curvature and the intrinsic out-of-plane electric polarization leads to layer-polarized near-quantized anomalous Hall conductance. Using first-principles calculations, we have identified a promising material for this model, namely FeS bilayer. Our calculations demonstrate that the intrinsic out-of-plane electric polarization in the Bernal-stacked FeS bilayer can induce QALHE by regulating the layer-locked Berry curvature of FeS monolayers. Importantly, the intrinsic electric filed can be reversed through interlayer sliding. The discovery of ferroelectrically modulated QALHE paves the way for the integrability and non-volatility of layertronics, offering exciting prospects for future applications.