Layer-polarization-engineered ferroelectricity and anomalous valley hall effects in a van der Waals bilayer.

Layertronics, engineering the electronic properties through the layer degree of freedom, has attracted considerable attention due to its promising applications in next-generation spintronic technologies. Here, by coupling sliding ferroelectricity with A-type antiferromagnetism, we demonstrate a mechanism for layer-polarization-engineered electronic property through symmetry analysis based on the tight-binding (TB) model. It is found that breaking the inversion symmetry and time-inversion symmetry in the model gives rise to ferroelectricity and a layer-polarized anomalous valley Hall effect. Crucially, this valley polarization is ferroelectrically switchable, enabling non-volatile electrical control of the layer-resolved Berry curvature. Using first-principles calculations, this mechanism and phenomenon are verified in the multiferroic bilayer Janus RuClF. Our findings provide a promising platform for 2D bilayer materials, which hold great potential for applications in nanoelectronic and spintronic devices.