An alternative numerical method to study spin transfer-induced magnetic reversals in nanopillar devices with non-zero damping

Abstract

In this paper, we present an alternative method to investigate spin transfer-induced magnetization changes in nano-pillars made of Heusler alloys by numerically solving the Landau-Lifshitz-Gilbert-Slonczewski (LLGS) with non-zero damping using the Runge-Kutta Method (RKM). We first developed the LLGS equation, including the spin-transfer torque term as well as the interface anisotropy field, and then numerically integrated the LLGS components using the Runge–Kutta algorithm. Asa result, stable processes of magnetization reversal were performed and analyzed according to the main parameters of the LLGS equation with/without interface anisotropy. Furthermore, the changes of switching time and threshold current density were also examined in the presence of interface anisotropy. The obtained results were compared with a systematic study of magnetization reversal using micromagnetic simulations. Accordingly, we found a very good agreement between the micromagnetic simulation and the RKM, both in terms of magnetization state and switching time.