Effects of Disorder and Internal Dynamics on Vortex Wall Propagation

TL;DR

This paper investigates how disorder and internal dynamics influence vortex domain wall propagation in magnetic nanowires, revealing that disorder affects velocity and energy dissipation, which are crucial for understanding magnetic device behavior.

Contribution

The study uses micromagnetic simulations to analyze the impact of disorder and internal dynamics on vortex wall motion, highlighting the role of effective damping and energy dissipation.

Findings

Disorder causes both increases and decreases in domain wall velocity.

Internal degrees of freedom are excited by disorder, increasing energy dissipation.

Effective damping increases with disorder, affecting wall propagation.

Abstract

Experimental measurements of domain wall propagation are typically interpreted by comparison to reduced models that ignore both the effects of disorder and the internal dynamics of the domain wall structure. Using micromagnetic simulations, we study vortex wall propagation in magnetic nanowires induced by fields or currents in the presence of disorder. We show that the disorder leads to increases and decreases in the domain wall velocity depending on the conditions. These results can be understood in terms of an effective damping that increases as disorder increases. As a domain wall moves through disorder, internal degrees of freedom get excited, increasing the energy dissipation rate.