First-Principles Studies of the Tunneling Properties through Ferroelectric/Ferromagnetic van der Waals Heterostructures

Two-dimensional (2D) ferroelectric/ferromagnetic van der Waals heterostructures (vdWHs) possess more than one ferric order and coupling effect, showing great application potential in information-processing devices. In the present work, we construct a graphene/In2Se3/CrI3/graphene vdWH to investigate its electronic and tunneling transport properties using first-principles calculations and the nonequilibrium Green function–density functional theory method. Two states are obtained in the vdWH, and they can be switched by the reversal of the polarization in the In2Se3 layer. One state shows nearly 100% spin-polarization around the Fermi level and another state with the opposite polarization direction shows no spin-polarization. Furthermore, in the transport property calculations, near-hole-conducting properties in one state and near-electron-conducting properties in another state are discovered, and they can be converted to each other with the polarization in In2Se3 reversed. Our results provide a new route to build an electric device in the nanoscale and to explore new potential applications of vdWHs.