Design parameters for field-free spin-orbit torque switching of perpendicular synthetic antiferromagnets

We report micromagnetic simulations of spin-orbit torque (SOT) induced magnetization switching of a ferromagnetic layer with perpendicular anisotropy in the absence of an external magnetic field. Field-free switching is achieved by antiferromagnetic interlayer exchange coupling (IEC) between two perpendicular ferromagnetic layers. At appropriate IEC values and an SOT current density exceeding the critical value (J(c)), magnetization reversal can be achieved within sub-ns. The complete magnetization reversal of the synthetic antiferromagnetic free layer occurs upon removing the current pulse. Higher damping is preferred for the proposed switching scheme, as J(c) decreases with the increase of damping. Remarkably, we also found that J(c) has a parabolic dependence on the nanomagnet's diameter, with the vertex occurring at 90nm.

Automated summary

Field-free magnetization switching of a ferromagnetic layer is achieved through spin-orbit torque (SOT) induced antiferromagnetic interlayer exchange coupling (IEC). Magnetization reversal can be achieved within sub-ns under appropriate conditions, with the complete reversal occurring upon removing the current pulse. Furthermore, the critical current density (J(c)) shows a parabolic dependence on the nanomagnet's diameter, with the vertex occurring at 90nm.