Spin Transport Properties of MnBi2Te4-Based Magnetic Tunnel Junctions

The van der Waals heterojunctions,stacking of different two-dimensional materials,have opened unprece-dented opportunities to explore new physics and device concepts.Here,combining the density functional theory with non-equilibrium Green's function technique,we systematically investigate the spin-polarized transport prop-erties of van der Waals magnetic tunnel junctions(MTJs),Cu/MnBi2Te4/MnBi2Te4/Cu and Cu/MnBi2Te4/h-BN/n·MnBi2Te4/Cu(n=1,2,3).It is found that the maximum tunnel magnetoresistance of Cu/MnBi2Te4/h-BN/3·MnBi2Te4/Cu MTJs can reach 162.6％,exceeding the system with only a single layer MnBi2Te4.More interestingly,our results indicate that Cu/MnBi2Te4/h-BN/n·MnBi2Te4/Cu(n=2,3)MTJs can realize the switching function,while Cu/MnBi2Te4/h-BN/3·MnBi2Te4/Cu MTJs exhibit the negative differential resistance.The Cu/MnBi2Te4/h-BN/3·MnBi2Te4/Cu in the parallel state shows a spin injection efficiency of more than 83.3％.Our theoretical findings of the transport properties will shed light on the possible experimental studies of MnBi2Te4-based van der Waals magnetic tunneling junctions.