Domain wall motion on magnetic nanotubes

In this paper the dynamical regimes of the motion of domain walls in magnetic nanotubes are studied theoretically. We compare results obtained with a simplified model of the magnetic energy with a detailed one that includes an exact treatment of the dipolar field. We demonstrate that the proper inclusion of dipolar effects changes qualitatively the mobility of a vortex domain wall driven by an applied magnetic field. We report that magnetic nanotubes display the characteristic phenomenology of domain wall motion: at low fields we find a steady motion with almost constant mobility (velocity/field) up to a critical field, where steady motion breaks out and a precessional motion appears. It is also found that the initial chirality of a vortex domain wall determines the dynamic regime of the motion near the Walker critical field. (C) 2010 American Institute of Physics. [doi:10.1063/1.3466747]