Point singularities and magnetization reversal in ideally soft ferromagnetic cylinders

Abstract

The principles of micromagnetics are used to describe the magnetization processes and magnetic configurations in a cylinder of finite length. The cylinder is of radius large compared to the exchange radius. Magnetostatic terms dominate in the limit that crystalline anisotropy is negligible. The exchange energy is minimized for boundary conditions primarily determined by magnetostatics. The point singularities required by topology are essential to understanding the process of magnetization. Complete reversal of magnetization is made possible by propagating point singularities down the axis of the cylinder. These propagating singularities arise from pair creation in a unit vector field.