Free Boundary Problems 2026

Existence and Structure of 360 degree walls in Thin Ferromagnetic Films

8 Sept 2026, 14:00

30m

DOR24/Floor 2-Room 205 - Lecture Hall (HU (Hegelplatz))

Domain Walls and Patterns in Local and Non-local Geometric Variational Problems Domain Walls and Patterns in Local and Non-local Geometric Variational Problems

Speaker

Hans Knüpfer (University of Heidelberg)

Description

We study the existence and structure of one-dimensional 360 degree walls in thin uniaxial ferromagnetic films. These structures are topological defects which consist of two oppositely charged 180 degree walls interacting by nonlocal stray-field energy. We show existence for nonzero wall angles when the stray-field interaction is sufficiently weak, while at zero angle no minimizer exists. We characterize scaling of the gruond state energy and the internal structure of the wall and obtain quantitative bounds on the separation of its two constituent sub-walls. This is joint work with A. Capella (UNAM) and C. Muratov (Pisa)