Designing non-volatile ferroelectric control of magnetic order in multiferroic In₂Se₃/bilayer...

The ferroelectric (FE) control of magnetism is of great importance for designing non-volatile, low-power-consumption memories. Existing studies mostly focus on monolayer ferromagnets, lacking exploration of spin-split mechanisms in bilayer antiferromagnets and multifunctional devices. Here, a two-dimensional (2D) multiferroic van der Waals (vdW) heterostructure (HS) with bilayer A-type antiferromagnet 1T-FeCl₂sandwiched between FE In₂Se₃was proposed to investigate the electronic structure using first-principles calculations. FE polarization directions of the top and bottom In₂Se₃layers were switched to obtain four polarization configurations of the HS. Although bilayer 1T-FeCl₂(bi-FeCl₂) still exhibits intralayer ferromagnetic (FM) and interlayer antiferromagnetic (AFM) coupling, FE polarization notably causes the spin-polarized splitting of the bi-FeCl₂bands (up to 0.34 eV), creating spin-up and spin-down polarized current channels in different layers of FeCl₂. This phenomenon is attributed to interfacial charge redistribution at the In₂Se₃/FeCl₂interface. Leveraging this, we designed a non-volatile, electric field-manipulated four-state spin field-effect transistor (FET), breaking the functional limitations of traditional single-switch devices and providing a specific strategy for spintronics research.