Quantum, shape and size effects in magnetization reversal

Macrospin approximation and quantum effects in models for magnetization reversal.
Mohammad Sayad, Daniel G¨utersloh and Michael Potthoff
ArXiv 1111.3900 (2011)

Sketch of the different magnetization-reversal mechanisms in the classical model for anisotropy strength D
smaller (macrospin model, coherent rotation) or larger (nucleation) than the critical value Dc and for infinite D (nucleation, vanishing domain-wall width) as verified by calculations for L = 4 spins.

Magnetization Reversal of Nanoscale Islands: How Size and Shape Affect the Arrhenius Prefactor.
S. Krause, G. Herzog, T. Stapelfeldt, L. Berbil-Bautista, M. Bode, E.Y. Vedmedenko, and R. Wiesendanger

Phys. Rev. Lett. 103, 127202 (2009)

(a) Experimentally determined prefactor as a function of island length. See labeled mesh inset for island correlation. (b) Prefactor from MC simulations. A tendency of decreasing is clearly visible. (c) Prefactor from MC simulations.