Magnetic tunnel junction based on bilayer LaI₂ as perfect spin filter device

The discovery of van der Waals intrinsic magnets has expanded the possibilities of realizing spintronics devices. We investigate the transmission, tunneling magnetoresistance ratio, and spin injection efficiency of bilayer LaI₂ using a combination of first-principles calculations and the non-equilibrium Green’s function method. Multilayer graphene electrodes are employed to build a magnetic tunnel junction with bilayer LaI₂ as ferromagnetic barrier. The magnetic tunnel junction turns out to be a perfect spin filter device with an outstanding tunneling magnetoresistance ratio of 653% under a bias of 0.1 V and a still excellent performance in a wide bias range. In combination with the obtained high spin injection efficiency this opens up great potential from the application point of view.