A comparison of two different mechanisms for deterministic spin orbit torque magnetization switching

In this article we analyze by modeling two possible mechanisms for magnetization switching using spin orbit torques, which have been reported to cause field-free deterministic switching in experiments. Here we compare the field-free magnetization switching due to a tilt of the anisotropy direction against the use of an antiferromagnetic bias field. Simple results obtained analytically show that a bias field not only causes the magnetization reversal but also reduces the corresponding energy barrier. The critical current required for magnetization switching is analyzed on the basis of a macrospin model. It is shown that although the field-free deterministic switching caused by a tilt of the anisotropy is more robust than the bias field in the development of memory elements, a compromise between requirements has to be adopted when selecting the parameters for specific applications.