Fast switching in a single-domain particle under sub-Stoner-Wohlfarth switching fields

We utilize an energy surface model and micromagnetic simulations to study fast switching in a single-domain particle under sub-Stoner-Wohlfarth switching fields. We show that for small damping and instantaneous field reversal, the switching field can be lower than the Stoner-Wohlfarth switching fields. For small field angles with respect to the anisotropy direction, the switching time decreases with decreasing field magnitude. The results are consistent with both micromagnetic simulations and experimental data. A simple physical explanation based on an energy surface model and the Landau-Lifshitz-Gilbert equation is given to explain these phenomena. (C) 2002 American Institute of Physics.