Switching Speedup of the Magnetic Free Layer of Advanced SOT-MRAM

We investigate the switching of a symmetric square and an elongated rectangular perpendicular free layer by spin-orbit torque with a magnetic field-free two-pulse scheme. The switching of the layer is achieved by utilizing the in-plane shape anisotropic magnetic field. For making the switching of a symmetric square layer deterministic, an in-plane stray field created in a part of the layer is used. The combination of the shape and stray fields accelerates the switching of the free layer significantly. A switching speedup factor of 3 to 5 has been obtained. The strategy also improves the robustness of the scheme allowing fast, sub-0.5 ns switching, less sensitive to the pulses' properties.