| Contents |
| Magnetic tunnel junction (MTJ) that compose of two ferromagnetic electrodes (recording and reference layers) sandwiching barrier layer is one of attractive systems for future electronics. In MTJs, information is stored as magnetization direction of the recording layer. For writing information, spin-transfer-torque (STT) is utilized by flowing current through MTJs. From application viewpoint, understanding of the switching by STT in ns regime is very important. The magnetization switching by STT is affected by relative magnetization angle between reference and recording layers. Because magnetization is fluctuated by thermal energy, there is distribution of initial relative magnetization angle, resulting in statistical switching behavior [1,2]. The statistical switching was also observed in domain wall motion by STT [3]. We will discuss the switching probability in ns regime for MTJ using CoFeB-MgO with perpendicular easy axis in which high performances were reported [4].
[1] D. Bedau et al., Appl. Phy. Lett. 97, 262502 (2010).
[2] J. He et al., J. Appl. Phys. 101, 09A501 (2007).
[3] S. Fukami et al., Nature. Communications, 4, 2293 (2013).
[4] S. Ikeda et al., Nature Mat. 9, 721 (2010).
Acknowledgement
This research is supported by the FIRST program from the JSPS and R&D for Next-Generation Information Technology of MEXT. |
|