Micromagnetic modeling of magnetization switching driven by spin-polarized current in magnetic tunnel junctions

This paper presents results of micromagnetic simulations of magnetization switching driven by spin-polarized current in magnetic tunnel junctions. For the studied structures, and for all the simulated currents, the switching occurs via nucleation process. A complete study of how a misalignment of the applied field and nonidealities in the shape of the sample affect the switching behavior has also been performed. The main results are as follows: (a) The switching mechanism does not change qualitatively by introducing a misalignment and (b) In contrast, the switching mechanism changes qualitatively when a nonideal shape is introduced. Lastly, simulations that include the effects of a 77K thermal bath are presented; these indicate that the switching times are shorter than for zero temperature simulations (sometimes also less than 50%).