Interfacial Control of both Magnetism and Polarization in a van der Waals Ferromagnet/Ferroelectric Heterostructure

Abstract: Two-dimensional multiferroic van der Waals heterostructures provide a promising platform for the simultaneous control of distinct ferroic orders, with potential applications in magnetoelectric devices and spintronics. The practical implementation of such technologies requires 2D magnets with high Curie temperatures and strong perpendicular magnetic anisotropy (PMA). Here, based on first-principles calculations, we propose a multiferroic heterostructure composed of the room-temperature ferromagnet $\text{Fe}_3\text{Ga}\text{Te}_2$ and the ferroelectric $\text{In}_2\text{Se}_3$. We show that intercalation of Fe atoms into the van der Waals gap of the $\text{Fe}_3\text{Ga}\text{Te}_2$/$\text{In}_2\text{Se}_3$ heterostructure enhances PMA by nearly an order of magnitude relative to the pristine $\text{Fe}_3\text{Ga}\text{Te}_2$ monolayer, while simultaneously allowing electric polarization to be modulated through interfacial charge redistribution. The enhancement of PMA arises from interfacial hybridization that modifies the spin-orbit coupling of Fe $d$-orbitals. Our results demonstrate an effective pathway to engineer magnetoelectric coupling in two-dimensional multiferroic heterostructures and pave the way toward energy-efficient spintronic devices.