论文标题
与杂质依赖性的旋转运动，偏转和电流驱动的超矩形Skyrmions在PDFE/IR（111）表面
Impurity-dependent gyrotropic motion, deflection and pinning of current-driven ultrasmall skyrmions in PdFe/Ir(111) surface
论文作者
论文摘要
在多尺度建模模拟的基础上，我们探索了动态方面的表征，这些方面是由自旋转移刺激的驱动的skyrmions朝着排斥力驱动的，并将3D和4D单个原子缺陷固定在嵌入在Fe/ir（111）表面上的PD层中。众所周知，后者可以容纳对信息技术引起的极大兴趣的低于10 nm的天空。 Landau-Lifshitz-Gilbert方程与从第一原理提取的磁交换相互作用进行了参数化。根据缺陷的性质和应用磁场的幅度，天空通过缩小或增加大小而变形，从而经历椭圆扭曲。在应用10个特斯拉的磁场后，将沿直线驱动到各种缺陷，从而可以简单地分析杂质的影响。与Skyrmion-Defect复合物相互作用的性质无关，观察到旋转运动。排斥力导致了与有吸引力的力量相似的天空轨迹。我们揭示了圆形运动在固定杂质周围顺时针方向，但在排斥性杂质周围逆时针，可以通过观察天空轨迹来识别缺陷的相互作用性质。此外，正如预期的那样，与固定缺陷相比，Skyrmion始终逃脱排斥的缺陷，这需要最小的滴定电流才能避免杂质。这揭示了Skyrmions运动方案的丰富性。我们根据硫素方程讨论了模拟的结果，该方程提供了对观察到的现象的合理定性描述。最后，我们展示了一个由固定杂质制成的双轨道的示例，其中它们的相互距离的工程允许以增强的速度控制天空运动。
Resting on multi-scale modelling simulations, we explore dynamical aspects characterizing skyrmions driven by spin-transfer-torque towards repulsive and pinning 3d and 4d single atomic defects embedded in a Pd layer deposited on the Fe/Ir(111) surface. The latter is known to host sub-10 nm skyrmions which are of great interest in information technology. The Landau-Lifshitz-Gilbert equation is parametrized with magnetic exchange interactions extracted from first-principles. Depending on the nature of the defect and the magnitude of the applied magnetic field, the skyrmion deforms by either shrinking or increasing in size, experiencing thereby elliptical distortions. After applying a magnetic field of 10 Tesla, ultrasmall skyrmions are driven along a straight line towards the various defects which permits a simple analysis of the impact of the impurities. Independently from the nature of the skyrmion-defect complex interaction a gyrotropic motion is observed. A repulsive force leads to a skyrmion trajectory similar to the one induced by an attractive one. We unveil that the circular motion is clockwise around pinning impurities but counter clockwise around the repulsive ones, which can be used to identify the interaction nature of the defects by observing the skyrmions trajectories. Moreover, and as expected, the skyrmion always escapes the repulsive defects in contrast to the pinning defects, which require a minimal depinning current to observe impurity avoidance. This unveils the richness of the motion regimes of skyrmions. We discuss the results of the simulations in terms of the Thiele equation, which provides a reasonable qualitative description of the observed phenomena. Finally, we show an example of a double track made of pinning impurities, where the engineering of their mutual distance allows to control the skyrmion motion with enhanced velocity.
