Dynamics of magnetic vortex core switching in Fe nanodisks by applying in-plane magnetic field pulse

We investigated the influence of the magnetic field pulse parameters and the size of the Fe element to the vortex core switching by micromagnetic modeling. When the magnetic field pulse with an appropriate strength and duration is applied to 30 nm thick Fe circular disks with diameters between 100 nm and 1 mu m, the vortex configuration is perturbed away from the equilibrium state, and the circular symmetric distribution of the in-plane magnetization around the vortex core deforms. This leads to the creation of a new vortex core with the opposite polarity and an antivortex. With increasing time, the vortex-antivortex pair annihilates. As a result of the annihilation, a single vortex core with opposite polarity remains and a vortex core switch is realized. The process of core switching, however, strongly depends on the amplitude and duration of the magnetic pulse. (c) 2007 American Institute of Physics.