Hole doped nonvolatile and electrically controllable magnetism in van der Waals ferroelectric heterostructures

Electrical control of magnetism in van der Waals semiconductors is a promising step toward developing two-dimensional ultralow-power-consumption spintronic devices for processing and storing information. Here, we propose a design for two-dimensional van der Waals heterostructures (vdWHs) that can host ferroelectricity and ferromagnetism simultaneously under hole doping. By contacting an InSe monolayer and forming an InSe/In2Se3 vdWH, the switchable built-in electric field from the reversible out-of-plane polarization enables robust control of the band alignment. Furthermore, switching between the two ferroelectric states (P↑ and P↓) of hole-doped In2Se3 with an external electric field can interchange the ON and OFF states of the nonvolatile magnetism. More interestingly, doping concentration and strain can effectively tune the magnetic moment and polarization energy. Therefore, this provides a platform for realizing multiferroics in ferroelectric heterostructures, showing great potential in nonvolatile memories and ferroelectric field-effect transistors.