Interacting Bloch lines: a new mechanism for wall energy in bubble domain materials

Abstract

The energy of an isolated vertical Bloch line in high-Q bubble materials is only a small fraction of the total wall energy. However, if there are so many Bloch lines along a domain wall that they are constrained to lie close to each other, their exchange energy becomes large. Calculations including this energy show qualitative agreement with the anomalous dependence of dimensions on bias field in certain bubbles and stripes in garnet films.