Tunable sliding ferroelectricity and magnetoelectric coupling in two-dimensional multiferroic MnSe materials

Sliding ferroelectricity (SFE) found in two-dimensional (2D) van der Waals (vdW) materials, such as BN and transition-metal dichalcogenides bilayers, opens an avenue for 2D ferroelectric materials. Multiferroic coupling in 2D SFE materials brings us an alternative concept for spintronic memory devices. In this study, using first-principles calculations, we demonstrate that MnSe multilayers constructed by the recently-synthesized MnSe monolayer have large sliding-driven reversible out-of-plane electric polarization (~10.6 pC m −1 ) and moderate interlayer sliding barriers superior to the existing 2D SFE materials. Interestingly, the intrinsic electric polarization is accompanied by nonzero net magnetic moments which are also switchable via lateral interlayer sliding. Additionally, both SFE and magnetoelectric coupling can be effectively regulated by external strain and/or hole doping. Our findings suggest the potential of MnSe multilayers in 2D multiferroic and spintronic applications.