Thermally induced magnonic spin current, thermomagnonic torques, and domain-wall dynamics in the presence of Dzyaloshinskii-Moriya interaction
Thermally induced magnonic spin current, thermomagnonic torques, and domain-wall dynamics in the presence of Dzyaloshinskii-Moriya interaction
复制标题
Dzyaloshinskii-Moriya 相互作用下的热感应自旋流、热磁矩和磁畴壁动力学
DOI：
10.1103/physrevb.94.104410
复制
发表时间：
2016-08
影响因子：
3.7
通讯作者：
Berakdar J.
中科院分区：
文献类型：
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作者：
Wang X. -G.;Chotorlishvili L.;Guo G. -H.;Sukhov A.;Dugaev V.;Barnas J.;Berakdar J.
本文从理论上研究了磁绝缘体中热激活畴壁运动，着重讨论了Dzyaloshinskiii-Moriya相互作用和热磁力矩的作用。热辅助DW运动是由于所施加的热偏置的磁振子自旋电流的结果。除了交换磁子自旋流和交换绝热和熵自旋转移力矩外，我们还考虑了DMI诱导的磁子自旋流、热磁子类场力矩和熵力矩。分析估计得到数值计算的支持。我们发现，纳米线的尺寸和几何形状的DW上有很大的影响，并且DW变得定向平行于纳米带的长轴。增加温度可使DW平滑。此外，热致磁振子电流在DW上产生扭矩，这是它们运动的原因。从我们的分析可以看出，对于一个足够大的磁势，DMI引起的类场力矩的影响要比磁势和交换熵力矩的影响强得多。通过操纵阻尼常数的强度，可以控制DW运动的速度，并且DW运动的方向也可以被切换。我们还发现，交换磁振子不仅对总磁振子电流有贡献，而且对交换磁振子自旋电流有修正作用，这种修正作用依赖于稳态磁化方向.所观察到的现象可用于自旋热电子器件，例如基于自旋热电子器件的热二极管。通过切换磁化方向，可以整流总的磁子自旋电流。
Thermally activated domain-wall (DW) motion in magnetic insulators has been considered theoretically, with a particular focus on the role of Dzyaloshinskii-Moriya interaction (DMI) and thermomagnonic torques. The thermally assisted DW motion is a consequence of the magnonic spin current due to the applied thermal bias. In addition to the exchange magnonic spin current and the exchange adiabatic and the entropic spin transfer torques, we also consider the DMI-induced magnonic spin current, thermomagnonic DMI fieldlike torque, and the DMI entropic torque. Analytical estimations are supported by numerical calculations. We found that the DMI has a substantial influence on the size and the geometry of DWs, and that the DWs become oriented parallel to the long axis of the nanostrip. Increasing the temperature smoothes the DWs. Moreover, the thermally induced magnonic current generates a torque on the DWs, which is responsible for their motion. From our analysis it follows that for a large enough DMI the influence of DMI-induced fieldlike torque is much stronger than that of the DMI and the exchange entropic torques. By manipulating the strength of the DMI constant, one can control the speed of the DW motion, and the direction of the DW motion can be switched, as well. We also found that DMI not only contributes to the total magnonic current, but also it modifies the exchange magnonic spin current, and this modification depends on the orientation of the steady-state magnetization. The observed phenomenon can be utilized in spin caloritronics devices, for example in the DMI based thermal diodes. By switching the magnetization direction, one can rectify the total magnonic spin current.
DOI：
--
发表时间：
2004
期刊：
--
影响因子：
--
作者：
L. Sehgal;J. V. Leusen
通讯作者：
L. Sehgal;J. V. Leusen