Investigating the Impact of Dzyaloshinskii–Moriya Interaction and Current Pulse Shape on Critical Current Density and Write Energy of SOT-MRAMs

The increasing demand for energy-efficient, reliable, and high-performance memory technologies has driven the development of spin-orbit torque magnetic random access memory (SOT MRAM). However, high write energy and slow switching dynamics are major challenges hindering the scalability and efficiency of SOT MRAM devices. To address these challenges, this study aims to optimize the write energy of SOT MRAM by investigating the role of the Dzyaloshinskii–Moriya interaction (DMI) and how it influences magnetization dynamics for different current pulse shapes and device dimensions. A multistep modeling approach is employed: first, finite element device simulations are performed using COMSOL, followed by spin drift diffusion calculations to obtain a spin current profile. These profiles are then integrated into the Object Oriented MicroMagnetic Framework (OOMMF) to analyze the magnetization dynamics. This study examines constant current pulse, descending triangle, and symmetric triangular pulse shapes with varying DMI to gauge the impact on switching performance. The descending triangle shape is found to have superior performance for low DMI, and all pulse shapes benefit to varying degrees from increased DMI.