Multiple modes of perpendicular magnetization switching scheme in single spin-orbit torque device

Spin-orbit torque (SOT) has been considered as one of the promising technologies for the next-generation magnetic random access memory (MRAM). So far, SOT has been widely utilized for inducing various modes of magnetization switching. However, it is a challenge that so many multiple modes of magnetization switching are integrated together. Here we propose a method of implementing both unipolar switching and bipolar switching of the perpendicular magnetization within a single SOT device. The mode of switching can be easily changed by tuning the amplitude of the applied current. We show that the field-like torque plays an important role in switching process. The field-like torque induces the precession of the magnetization in the case of unipolar switching, however, the field-like torque helps to generate an effective z-component torque in the case of bipolar switching. In addition, the influence of key parameters on the mode of switching is discussed, including the field-like torque strength, the bias field, and the current density. Our proposal can be used to design novel reconfigurable logic circuits in the near future.