A Universal Compact Model for Spin-Transfer Torque-Driven Magnetization Switching in Magnetic Tunnel Junction

Abstract

Current-induced magnetization switching through spin-transfer torque (STT) has shown great potential for low-power information storage. However, predicting its mesoscopic behavior induced by both electrical current and thermal fluctuation is a fundamental challenge in spintronics. Moreover, the physical models in different switching regimes have not been properly unified. Here, we propose a novel analytical model to describe the mean magnetization switching time in general terms. By incorporating a nondimensional parameter <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${k}$ </tex-math></inline-formula> in (0,1) to elucidate the relative impact of thermal activation and current, the unified model shows good agreement with the experimental data in all the regimes, including high current regime, thermal activation regime, and the intermediate regime between them. Finally, we develop an electrical model of magnetic tunnel junction (MTJ) device with Verilog-A language and perform transient simulation to demonstrate its functionality with Spectre. The Monte Carlo simulations have also been implemented to confirm their stochastic switching behavior. This model will be greatly beneficial for accurate and efficient designs for spintronic-based integrated circuits.