论文标题
超敏感的亚单层钯诱导的手性切换和拓扑演变
Ultrasensitive Sub-monolayer Palladium Induced Chirality Switching and Topological Evolution of Skyrmions
论文作者
论文摘要
手性旋转纹理从根本上很有趣，并且有希望使用设备应用。通常，通过在不对称的多层中引入dzyaloshinskii-moriya相互作用（DMI）来实现稳定手性，其中每层的厚度至少是几个单层。在这里，我们报告了仅使用0.22个PD单层封盖引起的（Ni/Co）N多层的超敏手性手性切换。使用自旋极化低能电子显微镜，我们监测域壁从左手到右腹壁的逐渐演变，并量化PD封顶层诱导的DMI。我们还观察到在DMI切换过程中Skyrmion的手性演变，因为Skyrmion绕组数变化了，在DMI开关中，没有发现明显的拓扑保护。这对应于Skyrmion手性切换期间的最低能量成本<1 attojoule。我们的结果表明，在DMI符号切换过程中，Skyrmions内部的手性演变与Skyrmionic设备的实际应用有关。
Chiral spin textures are fundamentally interesting, with promise for device applications. Stabilizing chirality is conventionally achieved by introducing Dzyaloshinskii-Moriya interaction (DMI) in asymmetric multilayers where the thickness of each layer is at least a few monolayers. Here we report an ultrasensitive chirality switching in (Ni/Co)n multilayer induced by capping with only 0.22 monolayer of Pd. Using spin-polarized low-energy electron microscopy, we monitor the gradual evolution of domain walls from left-handed to right-handed Neel walls and quantify the DMI induced by the Pd capping layer. We also observe the chiral evolution of a skyrmion during the DMI switching, where no significant topological protection is found as the skyrmion winding number varies. This corresponds to a minimum energy cost of < 1 attojoule during the skyrmion chirality switching. Our results demonstrate the detailed chirality evolution within skyrmions during the DMI sign switching, which is relevant to practical applications of skyrmionic devices.
