Thermally assisted spin transfer torque switching in synthetic free layers
Abstract
We studied the magnetization reversal rates of thermally assisted spin transfer torque switching in a ferromagnetically coupled synthetic free layer theoretically. By solving the Fokker-Planck equation, we obtained the analytical expression of the switching probability for both the weak and the strong coupling limit. We found that the thermal stability is proportional to Delta_{0}(1-I/I_{c})^{2}, not Delta_{0}(1-I/I_{c}) argued by Koch et al. [Phys. Rev. Lett. 92, 088302 (2004)], where I and I_{c} are the electric current and the critical current of spin transfer torque switching at absolute zero temperature. The difference in the exponent of (1-I/I_{c}) leads to a significant underestimation of the thermal stability Delta_{0}. We also found that fast switching is achieved by choosing the appropriate direction of the applied field.
Cite
@article{arxiv.1010.5845,
title = {Thermally assisted spin transfer torque switching in synthetic free layers},
author = {Tomohiro Taniguchi and Hiroshi Imamura},
journal= {arXiv preprint arXiv:1010.5845},
year = {2011}
}