Hybrid Switching of Perpendicular Magnetization in Assistance With In-Plane Uniaxial Shape Anisotropy

The spin–orbit torque (SOT) mechanism is a highly efficient method for switching the magnetization of magnetic tunnel junctions (MTJs) with perpendicular anisotropy. However, the need for an in-plane magnetic field for the deterministic switching of MTJs restricts their practical applications. Hence, a hybrid approach of the spin-transfer torque (STT) along with SOT is often employed. An alternate approach for field-free switching is to use an elliptical MTJ whose axis is tilted at a certain angle with that of a heavy metal. This method uses in-plane uniaxial shape anisotropy along with SOT for deterministic switching. Here, we study a five-terminal perpendicular magnetic anisotropy (PMA) MTJ having an elliptical cross section, switched using both the hybrid approach and the uniaxial shape anisotropy. The switching probability of this device is simulated using the Landau–Lifshitz–Gilbert (LLG) equation and compared to that of a three-terminal MTJ having a circular cross section. Our results show that the elliptical MTJ exhibits better switching probability than the circular MTJ. Additionally, we analyze key parameters that can enhance the switching probability of the elliptical MTJ.