Spin-transfer torque induced reversal in magnetic domains

TL;DR

This paper demonstrates that spin-transfer torque can effectively induce magnetic domain reversal in macrospins, offering a more efficient alternative to external magnetic fields, with potential applications in magnetic memory devices.

Contribution

The study introduces a novel representation of the macrospin dynamics and shows that spin-transfer torque can reliably switch magnetic states more efficiently than traditional magnetic field methods.

Findings

Spin-transfer torque acts like an effective magnetic field.

Short spin-polarized current pulses can switch macrospin states.

Switching via spin-transfer torque is more efficient than external fields.

Abstract

Using the complex stereographic variable representation for the macrospin, from a study of the nonlinear dynamics underlying the generalized Landau-Lifshitz(LL) equation with Gilbert damping, we show that the spin-transfer torque is effectively equivalent to an applied magnetic field. We study the macrospin switching on a Stoner particle due to spin-transfer torque on application of a spin polarized current. We find that the switching due to spin-transfer torque is a more effective alternative to switching by an applied external field in the presence of damping. We demonstrate numerically that a spin-polarized current in the form of a short pulse can be effectively employed to achieve the desired macro-spin switching.