A Compact Model of Perpendicular Spin-Transfer-Torque Magnetic Tunnel Junction

We present a new compact model of a perpendicular spin-transfer-torque (STT) magnetic tunnel junction (MTJ). Previous studies on STT-MTJs have either focused on solving the Landau-Lifshitz-Gilbert (LLG) equation or utilizing critical current-based macro models. However, the LLG approaches are too complex for large circuit simulations, while the macro models fail to capture the underlying magnetization physics. In this work, we propose a semiphysical and computationally efficient compact model that accurately represents the time-dependent magnet moment and resistance. To validate our model, we compare it with various experimental data and LLG-based STT-MTJ model. The model demonstrates geometry dependence and temperature dependence. Furthermore, we develop a continuous switching probability model to effectively track the probabilities of states under arbitrary waveforms.