Curvature induced domain wall pinning

TL;DR

This paper demonstrates that local bends in nanowires create pinning sites for domain walls, with their oscillation frequencies and friction influenced by curvature, supported by micromagnetic simulations.

Contribution

It introduces a theoretical model linking wire curvature to domain wall pinning and verifies it through micromagnetic simulations for parabolic bends.

Findings

Curvature induces a pinning potential for domain walls.

Eigenfrequency of oscillations depends on curvature and domain wall width.

Micromagnetic simulations confirm the theoretical predictions.

Abstract

It is shown that a local bend of a nanowire is a source of pinning potential for a transversal head-to-head (tail-to-tail) domain wall. Eigenfrequency of the domain wall free oscillations at the pinning potential and the effective friction are determined as functions of the curvature and domain wall width. The pinning potential originates from the effective curvature induced Dzyaloshinsky-like term in the exchange energy. The theoretical results are verified by means of micromagnetic simulations for the case of parabolic shape of the wire bend.