Thickness dependence of spin torque effect in Fe/MgO/Fe magnetic tunnel junction: Implementation of divide-and-conquer with first-principles calculation

In this study, we develop a divide-and-conquer (DC) method under the framework of first-principles calculation to prevent directly solving Hamiltonian large device with time-consuming self-consistent process. The DC implementation combined JunPy package reveals oscillatory decay layer-resolved spin torques away from MgO/Fe interface, and suggests very thin Fe layer thickness below 2 nm preserve efficient current-driven magnetization switch. This newly developed JunPy-DC may efficiently resolve current difficulties in noncollinear torque effects for novel spintronic applications complex magnetic heterostructures.