Transition from the macrospin to chaotic behaviour by a spin-torque driven magnetization precession of a square nanoelement

摘要

We demonstrate (using full-scale micromagnetic simulations) that the spininjection driven steady-state precession of a thin magnetic nanoelement exhibita complicate transition from the quasi-macrospin to the chaotic behaviour withthe increasing element size. For nanoelement parameters typical for those usedexperimentally we have found that the macrospin approximation becomes invalidalready for very small nanoelement sizes (~ 30 nm), in contrast to thepreviously reported results (Li and Zhang, Phys. Rev. B, vol. B68, 024404-1(2003))