Dual Control of Giant Field-Like Spin Torque in Spin Filter Tunnel Junction

Recent discoveries in the ferromagnet/insulator/ferromagnet (FM/I/FM) magnetic tunnel junctions (MTJs) have demonstrated that the relative orientation of the two FM electrodes can be either altered by an external magnetic field, i.e. the tunneling magnetoresistance (TMR) effect, or controlled by a spin-polarized current, i.e. the current-induced magnetization reversal via the spin transfer torque (STT) effect. The spin-transfer, $\text{T}_{\Vert}$ , and field-like, $\text{T}_{\perp}$ , components of the STT originate from different components of the spin current accumulated at the FM/I interface and can be expressed in terms of the interplay of spin current densities and of the non-equilibrium interlayer exchange couplings [1], respectively, solely in collinear configurations.