Modular Compact Modeling of Magnetic Tunnel Junction Devices

This paper describes a robust, modular, and physics- based circuit framework to model conventional and emerging Magnetic Tunnel Junction (MTJ) devices. Magnetization dynamics are described by the stochastic Landau-Lifshitz-Gilbert (sLLG) equation whose results are rigorously benchmarked with a Fokker-Planck Equation (FPE) description of magnet dynamics. We then show how sLLG is coupled to transport equations of MTJ-based devices in a unified circuit platform. Step by step, we illustrate how the physics-based MTJ model can be extended to include different spintronics phenomena, including spin-transfer-torque (STT), voltage-control of magnetic anisotropy (VCMA) and spin-orbit torque (SOT) phenomena by experimentally benchmarked examples. To demonstrate how our approach can be used in the exploration of novel MTJ-based devices, we also present a recently proposed MEMS resonator- driven spin-torque nano oscillator (STNO) that can reduce the phase noise of STNOs. We briefly elaborate on the use of our framework beyond conventional devices.