1210.1358 (Thomas Nattermann)

A model for elasticity and pinning of domain walls in helical magnets    [PDF]

Thomas Nattermann

The theory of elasticity and coercivity of domain walls in both, centrosymmetric and noncentrosymmetric helical magnets, is developed. Generically these walls consist of regular arrays of magnetic vortex lines. Exceptions are walls oriented along high symmetry directions. The elasticity of the latter turns out to be non-local below their roughening transition, pinning of these walls by disorder is negligible. In contrast, weak anisotropy, breaking the U(1) symmetry of the helix, results in domain wall pinning by the bulk. Walls of other orientations consist of pairs of vortex lines separated by vortex free parts. These are strongly pinned by disorder. The application to chiral liquid crystals is briefly discussed.

View original: http://arxiv.org/abs/1210.1358