Ferroelectrically reversible PL-AHE in multiferroic heterostructures of rare-earth iodides

Layer-polarized anomalous Hall effect (LP-AHE), arising from the coupling between valley-contrasting Berry curvature and the layer degree of freedom, is a fundamental phenomenon in condensed matter physics and spintronics. In this work, using first-principles calculations, we demonstrate that the LP-AHE can be established in GdCeI4, a rare-earth iodide (RI2) multiferroic heterostructure. In GdCeI4, the layer degree of freedom enables direct coupling between ferroelectricity and valley-contrasting Berry curvature. Layer-dependent valley polarization is tunable by sliding ferroelectricity, while valley-contrasting Berry curvature is switched by altering the magnetization orientation. The LP-AHE can also be achieved and switched in GdCeBr4. In two other RI2 heterostructures, GdYI4 and GdLaI4, the sliding ferroelectricity is also achieved, but the layer polarization cannot be switched by sliding ferroelectricity. The layer-valley coupling also enables the control of LP-AHE via an applied gate voltage. Our work provides an alternative route to construct LP-AHE systems.