Jm. Sun et Wl. Luo, DYNAMICS OF LOW-DIMENSIONAL DIPOLAR SYSTEMS, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 56(4), 1997, pp. 3986-3992
Time decays of low-dimensional magnetic dipoles with anisotropic energ
y barriers were studied theoretically. We found that the dynamic behav
iors are interaction specific. For a chain with ferromagnetic coupling
, a single mode dominates and the decay is essentially exponential. Fo
r antiferromagnetic coupling, the dynamics can be characterized by two
distinct groups of time scales. The spectrum results in a plateau in
the decay of remanent magnetization. This novel behavior differs from
the prediction of the mean-field theory. For a two-dimensional rectang
ular lattice, a transition between the bimodal decay and a quasilogari
thmic decay occurs when the ratio of length to width varies.