Screw-pitch effect and velocity oscillation of a domain wall in a ferromagnetic nanowire driven by spin-polarized current
Screw-pitch effect and velocity oscillation of a domain wall in a ferromagnetic nanowire driven by spin-polarized current
复制标题
DOI：
10.1088/0953-8984/22/21/216001
复制
发表时间：
2010-04
期刊：
影响因子：
--
通讯作者：
Zaidong Li;Qiu-Yan Li;X. R. Wang;W. M. Liu;J. Q. Liang;G. Fu
中科院分区：
文献类型：
--
作者：
Zaidong Li;Qiu-Yan Li;X. R. Wang;W. M. Liu;J. Q. Liang;G. Fu
我们研究了具有自旋转移矩的铁磁纳米线中畴壁的动力学行为。解析地得到了临界电流条件。在临界电流以下，我们得到了静态畴壁解，表明自旋极化电流不能驱动畴壁连续运动。在这种情况下，自旋转移力矩起到了反旋进和反阻尼的作用，它不仅抵消了有效场驱动的自旋旋进，而且抵消了力矩的吉尔伯特阻尼。在临界值以上，畴壁的动力学表现出新颖的螺距效应，其特征在于畴壁速度和宽度的时间振荡，分别。理论分析和数值模拟均表明，这种现象是由于吉尔伯特阻尼和自旋转移力矩共同作用的结果。我们还发现，自旋转移力矩的作用是完全相反的情况下，低于和高于临界电流。
We investigate the dynamics of a domain wall in a ferromagnetic nanowire with spin-transfer torque. The critical current condition is obtained analytically. Below the critical current, we get the static domain wall solution, which shows that the spin-polarized current cannot drive a domain wall moving continuously. In this case, the spin-transfer torque plays both the anti-precession and anti-damping roles, which counteracts not only the spin precession driven by the effective field but also Gilbert damping of the moment. Above the critical value, the dynamics of the domain wall exhibits the novel screw-pitch effect characterized by the temporal oscillation of domain wall velocity and width, respectively. Both the theoretical analysis and numerical simulation demonstrate that this novel phenomenon arises from the conjunctive action of Gilbert damping and spin-transfer torque. We also find that the roles of spin-transfer torque are completely opposite for the cases below and above the critical current.