Designing van der Waals magnetic tunnel junctions with high tunnel magnetoresistance <i>via</i> Brillouin zone filtering
Kun Li, Yuzheng Guo, John Robertson, Weisheng Zhao, Haichang Lu
Abstract
= 3 and 4) are calculated to have high transmission coefficients over the entire in-plane BZ for the majority spin channel, while this should only happen around Γ for the minority spin channel. Correspondingly, various 2H-type transition metal dichalcogenides (TMDs) are found to function effectively as spin barriers, where electrons are only allowed to tunnel through them around the K and M points. BZ spin filtering is confirmed to be the major mechanism of the TMR effect by the MTJ transport calculation using the non-equilibrium Green function method. Furthermore, the TMR is calculated to be nearly independent of the barrier layer thickness as the BZ filtering is an interfacial effect. This work sheds light on material selection procedures and designing ultra-thin and robust van der Waals MTJs.