Tunneling Magnetoresistance of Bilayer Hexagonal Boron Nitride and Its Linear Response to External Uniaxial Strain

Using density functional theory and nonequilibrium Green's function method, we investigate the tunneling magnetoresistance (TMR) of the magnetotunnel junctions (MTJs) based on bilayer hexagonal boron nitride and its response to external uniaxial strain. The TMR ratio increases linearly with the increasing uniaxial strain because the increasing uniaxial strain reduces the bandgap of bilayer hexagonal boron nitride gradually. Interestingly, the TMR ratio exceeds 95% when the uniaxial strain increases to 2.51%, which is close to that of the perfect spin filter. Our results indicate that the bilayer hexagonal boron nitride is a promising candidate for the spacer of MTJs. Moreover, its TMR. ratio can be linearly modulated by external uniaxial strain.