Nonvolatile magnetoelectric coupling in two-dimensional van der Waals sandwich heterostructure...

Electrical control of magnetism is of great interest for low-energy-consumption spintronic applications. Due to the recent experimental breakthrough in two-dimensional materials, with the absence of hanging bonds on the surface and strong tolerance for lattice mismatch, heterogeneous integration of different two-dimensional materials provides a new opportunity for coupling between different physical properties. Here, we report the realization of nonvolatile magnetoelectric coupling in vdW sandwich heterostructure CuInP₂S₆/MnCl₃/CuInP₂S₆. Using first-principles calculations, we reveal that when interfacing with ferroelectric CuInP₂S₆, the Dirac half-metallic state of monolayer MnCl₃ will be destroyed. Moreover, depending on the electrically polarized direction of CuInP₂S₆, MnCl₃ can be a half-metal or a ferromagnetic semiconductor. We unveil that the obtained ferromagnetic semiconductor in MnCl₃ can be attributed to the different gain and loss of electrons on the two adjacent Mn atoms due to the sublattice symmetry broken by interlayer coupling. The effects of interfacial magnetoelectric coupling on magnetic anisotropy and ferromagnetic Curie temperature of MnCl₃ are also investigated, and a multiferroic memory based on this model is designed. Our work not only provides a promising way to design nonvolatile electrical control of magnetism but also renders monolayer MnCl₃ an appealing platform for developing low-dimensional memory devices.