论文标题
手性阻尼对手性域壁和天空动力学的影响
Effect of Chiral Damping on the dynamics of chiral domain walls and skyrmions
论文作者
论文摘要
摩擦在我们日常生活中经历的大多数物理过程中起着至关重要的作用。示例范围从我们的步行或游泳能力到设定移动车辆的速度和燃油效率的界限。在磁系统中,旋转轨道扭矩(SOT)的手性结构域壁(DW)和Skyrmions(SK)的位移也容易发生摩擦。手性阻尼是Dzyaloshinskii Moriya相互作用(DMI)的耗散性对应物,在这些动力学中起着核心作用。尽管实验性观察以及许多理论研究证实了其存在,但由于难以区分DMI,手性阻尼对DW和SK动力学的影响仍然难以捉摸。在这里,我们揭示了手性阻尼对电流和磁场驱动的DW和SK的流动的影响。我们使用静态的平面场来提升手性退化。随着面内场的增加,手性不对称变化符号。当单独考虑时,DMI和手性阻尼都无法解释不对称性的符号逆转,我们被证明是它们竞争作用的结果。最后,数值建模揭示了手性耗散的非线性性质及其在移动SK稳定中的关键作用。
Friction plays an essential role in most physical processes that we experience in our everyday life. Examples range from our ability to walk or swim, to setting boundaries of speed and fuel efficiency of moving vehicles. In magnetic systems, the displacement of chiral domain walls (DW) and skyrmions (SK) by Spin Orbit Torques (SOT), is also prone to friction. Chiral damping, the dissipative counterpart of the Dzyaloshinskii Moriya Interaction (DMI), plays a central role in these dynamics. Despite experimental observation, and numerous theoretical studies confirming its existence, the influence of chiral damping on DW and SK dynamics has remained elusive due to the difficulty of discriminating from DMI. Here we unveil the effect that chiral damping has on the flow motion of DWs and SKs driven by current and magnetic field. We use a static in-plane field to lift the chiral degeneracy. As the in-plane field is increased, the chiral asymmetry changes sign. When considered separately, neither DMI nor chiral damping can explain the sign reversal of the asymmetry, which we prove to be the result of their competing effects. Finally, numerical modelling unveils the non-linear nature of chiral dissipation and its critical role for the stabilization of moving SKs.