Strain controlling transport properties of heterostructure composed of monolayer CrI3

The modulation of the magnetic state and spin orientation in two-dimensional (2D) intrinsic magnets is important for controlling the spin-dependent transport properties of 2D magnet-based heterostructures. In this work, using first-principles calculations, it is found that the Néel antiferromagnetic (AFM) state with in-plane spin and the ferromagnetic (FM) state with in-plane and out-of-plane spin can be achieved in monolayer CrI3 under appropriate in-plane strains. In particular, the conductance of the Graphite/monolayer-CrI3/Graphite van der Waals heterostructure increases with the increase in the tensile strain, and the rate of change in conductance reaches more than 1800% when the strain becomes larger than 20%, which is significantly larger than that of the van der Waals heterostructure with a nonmagnetic insulator as a barrier to the magnetic field. Interestingly, when the magnetic state in monolayer CrI3 is switched from the Néel AFM to FM state by strain, the anisotropy magnetoresistance (AMR) ratio of the Graphite/monolayer-CrI3/Graphite heterostructure changes from −34.8% to 70%. The changes of AMR and conductance with strain originate mainly from the variation of the bandgap of monolayer CrI3 and the average transmission channels of graphite. These findings enrich the method in tuning spin orientation and provide the route for controlling transport properties of the heterostructure by strain tuning spin orientation in 2D magnets.