Switching diagrams of nanoscale ferromagnets driven by a spin-transfer torque are studied in the macrospin approximation. We consider a disk-shaped free layer with in-plane easy axis and external magnetic field directed in-plane at 90 degrees to that axis. It is shown that this configuration is sensitive to the angular dependence of the spin-transfer efficiency factor and can be used to experimentally distinguish between different forms of g(θ), in particular between the original Slonczewski form and the constant g approximation. The difference in switching diagrams is especially pronounced at large spin polarizations, with the Slonczewski case exhibiting an anomalous region.
@article{arxiv.0906.4566,
title = {Anomalous stabilization in a spin-transfer system at high spin polarization},
author = {Inti Sodemann and Ya. B. Bazaliy},
journal= {arXiv preprint arXiv:0906.4566},
year = {2009}
}