Yichen Shen, Olga Petrova, Paula Mellado, Stephen Daunheimer, John Cumings, Oleg Tchernyshyov
We model the dynamics of magnetization in an artificial analog of spin ice
specializing to the case of a honeycomb network of connected magnetic
nanowires. The inherently dissipative dynamics is mediated by the emission,
propagation and absorption of domain walls in the links of the lattice. These
domain walls carry two natural units of magnetic charge, whereas sites of the
lattice contain a unit magnetic charge. Magnetostatic Coulomb forces between
these charges play a major role in the physics of the system, as does quenched
disorder caused by imperfections of the lattice. We identify and describe
different regimes of magnetization reversal in an applied magnetic field
determined by the orientation of the applied field with respect to the initial
magnetization. One of the regimes is characterized by magnetic avalanches with
a 1/n distribution of lengths.
View original:
http://arxiv.org/abs/1112.1857
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