Spin torque switching of an in-plane magnetized system in a thermally activated region
| Autor: | Taniguchi, Tomohiro, Utsumi, Yasuhiro, Marthaler, Michael, Golubev, Dmitri S., Imamura, Hiroshi |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | Physical Review B 87, 054406 (2013) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.87.054406 |
| Popis: | The current dependence of the exponent of the spin torque switching rate of an in-plane magnetized system was investigated by solving the Fokker-Planck equation with low temperature and small damping and current approximations. We derived the analytical expressions of the critical currents, I_{c} and I_{c}^{*}. At I_{c}, the initial state parallel to the easy axis becomes unstable, while at I_{c}^{*} (\simeq 1.27 I_{c}) the switching occurs without the thermal fluctuation. The current dependence of the exponent of the switching rate is well described by (1-I/I_{c}^{*})^{b}, where the value of the exponent b is approximately unity for I < I_{c}, while b rapidly increases up to 2.2 with increasing current for I_{c} < I < I_{c}^{*}. The linear dependence for I < I_{c} agrees with the other works, while the nonlinear dependence for I_{c} < I < I_{c}^{*} was newly found by the present work. The nonlinear dependence is important for analysis of the experimental results, because most experiments are performed in the current region of I_{c} < I < I_{c}^{*}. Comment: 10 pages, 8 figures |
| Databáze: | arXiv |
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