Computational Study for Spin-orbit Torque Magnetic Random Access Memory

Abstract

We provide the first comprehensive computational study of spin-orbit torque magnetic random access memory (SOT-MRAM) device. A framework combining ab initio and micromagnetic/macrospin simulations is proposed to probe into the key performances of SOT-MRAM device, i.e., the power consumption, read error rate and speed. Specifically, using density functional theory (DFT) coupled with maximally localized Wannier function (MLWF) and non-Equilibrium Green's function (NEGF), we calculate the intrinsic spin Hall conductivity (SHC) and the tunneling magnetoresistance (TMR) of SOT magnetic tunnel junctions (MTJs). Based on the SHC results and related experimental parameters, we analyze the write performance by Landau-Lifshitz-Gilbert (LLG) equation. Under this computational framework, we show that IrMn with broken magnetic symmetry is promising to satisfy the requirements for high performance SOT-MRAM. Our work paves the way to exploit new materials and optimize SOT-MRAM, which will accelerate both the theoretical and the related experimental research.