Ultrafast vortex-core reversal dynamics in ferromagnetic nanodots
Ultrafast vortex-core reversal dynamics in ferromagnetic nanodots
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DOI：
10.1103/physrevb.76.174410
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发表时间：
2007-11-01
影响因子：
3.7
通讯作者：
Kim, Sang-Koog
中科院分区：
文献类型：
--
作者：
Lee, Ki-Suk;Guslienko, Konstantin Y.;Kim, Sang-Koog
为了验证超快涡核反转的确切机制以及涡旋状态的稳定性，我们对坡莫合金圆柱形纳米点中的磁涡旋在宽范围的场频率和振幅的振荡面内磁场下的动态演化进行了数值计算。计算结果揭示了涡对驱动外场的各种非平凡动力学响应，包括涡核反转。特别是，研究结果提供了深入了解10 ps尺度的超快涡核反转驱动的小振幅（类似于10 Oe）振荡面内场的物理。这项工作也提供了如何有效地操纵涡动力学以及涡核方向的动态切换的基础。
To verify the exact underlying mechanism of ultrafast vortex-core reversal as well as the vortex state stability, we conducted numerical calculations of the dynamic evolution of magnetic vortices in Permalloy cylindrical nanodots under an oscillating in-plane magnetic field over a wide range of the field frequency and amplitude. The calculated results reveal different kinds of the nontrivial dynamic responses of vortices to the driving external field, including the vortex-core reversal. In particular, the results offer insight into the 10 ps scale underlying physics of the ultrafast vortex-core reversal driven by small-amplitude (similar to 10 Oe) oscillating in-plane fields. This work also provides fundamentals of how to effectively manipulate the vortex dynamics as well as the dynamical switching of the vortex-core orientation.