Micromagnetic study of picosecond dephasing of spin waves in a square magnetic element

We present the micromagnetic simulation of picosecond dephasing of spin waves in a square micromagnetic element. Application of a fast magnetic field pulse produces stripes in the time-dependent magnetic images due to the presence of multiple spin waves. Frequencies of the spin waves were extracted from spatial sampling of time-dependent magnetization. We excite the individual spin waves by monochromatic harmonic fields oscillating at frequencies of the observed spin waves in micromagnetic simulations. This allows us to understand the spatial nature of the spin waves and that the observed stripes in time-resolved magnetic images are a consequence of superposition of a number of noninteracting resonant modes in that magnetic element. (C) 2007 American Institute of Physics.