Effect of Spin Torque on Magnetization Switching Speed Having Nonuniform Spin Distribution

TL;DR

This paper investigates how nonuniform spin torque influences the speed of magnetization switching in ferromagnetic particles, revealing that spin vortices can significantly alter reversal times.

Contribution

It introduces a model incorporating space-dependent spin torque effects into magnetization dynamics, highlighting the role of spin vortices in switching speed.

Findings

Spin torque significantly affects magnetization reversal time.

Spin vortices can maintain intermediate states during switching.

Reversal speed can be controlled via spin torque manipulation.

Abstract

We study the influence of the spin torque, which depends on the space and time derivative of magnetization, on magnetization reversal time in a ferromagnetic fine particle. The spin torque operates to dissipate the angular momentum of the magnetization precession, and the torque increases in a spin vortex structure. We calculate the magnetization reversal time under a DC magnetic field using the Landau-Lifshitz-Gilbert equation containing a spin torque term. We found that the spin torque changes the magnetization switching speed significantly during the reversal process by maintaining a spin vortex in an intermediate state.