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arXiv · 1010.5845

Thermally assisted spin transfer torque switching in synthetic free layers

Tomohiro Taniguchi·Hiroshi Imamura
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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.

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Tomohiro Taniguchi, Hiroshi Imamura. 2011-02-24. Thermally assisted spin transfer torque switching in synthetic free layers. https://doi.org/10.1103/physrevb.83.054432

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