Micromagnetic simulation of precessional switching

Precessional switching of information bits may prove to be an alternative of traditional “hysteretic” switching in magnetic memory devices. The experimental studies of this new “write-in” process have manifested unwanted fluctuations, which may pose a limit to its technological applicability. A possible origin of the fluctuations might be the uncertainty principle. We present a quantum-mechanical one-electron magnetic model based on the classical Landau-Lifshitz-Gilbert equation in order to be able to calculate the uncertainties of the switching process. The Schrödinger equation describing the dynamical behavior of a spin can be useful for modeling spintronics-related processes too. We have examined a precessional switching experiment carried out in a CoCrPt layer of perpendicular magnetization. The observed irregular behavior was attributed to the fluctuations of the magnetization caused by the extremely strong and short switching pulses. We could not confirm any relation to extremities, the grain structure of the storage medium can account regularly for the observed experimental findings.