Static properties and current-induced dynamics of pinned $90$ degree magnetic domain walls under applied fields: an analytic approach

TL;DR

This paper develops an analytical model for the static and current-driven dynamic behavior of 90-degree pinned magnetic domain walls, providing insights into their resonance properties and response to external stimuli.

Contribution

It introduces a new analytical framework and discrete Heisenberg model specifically for pinned 90-degree magnetic domain walls, enhancing understanding of their static and dynamic properties.

Findings

Model accurately predicts domain wall resonance frequency.

Resonance frequency varies with anisotropy strength and magnetic field.

Analytical results agree with micromagnetic simulations.

Abstract

Magnetic domain walls are pinned strongly by abrupt changes in magnetic anisotropy. When driven into oscillation by a spin-polarized current, locally pinned domain walls can be exploited as tunable sources of short-wavelength spin waves. Here, we develop an analytical framework and discrete Heisenberg model to describe the static and dynamic properties of pinned domain walls with a head-to-tail magnetic structure. We focus on magnetic domain walls that are pinned by 90$^\circ$ rotations of uniaxial magnetic anisotropy. Our model captures the domain wall response to a spin-transfer torque that is exerted by an electric current. Model predictions of the domain wall resonance frequency and its evolution with magnetic anisotropy strength and external magnetic field are compared to micromagnetic simulations.