Electric Field Effects on Magnetism in CrI3 Bilayers
Shuanglong Liu1,2, Yun-Peng Wang1,2, Long Zhang1,2, James N. Fry1, and Hai-Ping Cheng1,2,3
1 Department of Physics, 2 Quantum Theory Project, and 3 Center for Molecular Magnetic Quantum Materials, University of Florida, Gainesville, FL 32611
Email: shlufl@ufl.edu
Magnetism in two dimensional (2D) materials has recently become a hot research topic due to its potential applications in spintronics and its interesting physical origin. Previous studies revealed that bilayer CrI3 exhibits intralayer ferromagnetic (FM) coupling and interlayer antiferromagnetic (AFM) coupling. By first-principles calculations, we show that the interlayer AFM coupling arises from enhanced Hubbard U for Cr atoms as the thickness of CrI3 decreases. Furthermore, the interlayer magnetic coupling can be switched from AFM to FM by applying an electric field. When the bilayer CrI3 is sandwiched between graphene or boron nitride sheets, a stronger electric field is needed to induce the magnetic phase transition. In addition, we may also present electron transport properties of a vertical tunneling junction involving bilayer CrI3 and graphene.