Karna Sunil K, Marshall Madalynn, Xie Weiwei, DeBeer-Schmitt Lisa, Young David P, Vekhter Ilya, Shelton William A, Kovács Andras, Charilaou Michalis, DiTusa John F
Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
Department of Physics and Center for Materials Research, Norfolk State University, Norfolk, Virginia 23504, United States.
Nano Lett. 2021 Feb 10;21(3):1205-1212. doi: 10.1021/acs.nanolett.0c03199. Epub 2021 Jan 25.
The control of domain walls is central to nearly all magnetic technologies, particularly for information storage and spintronics. Creative attempts to increase storage density need to overcome volatility due to thermal fluctuations of nanoscopic domains and heating limitations. Topological defects, such as solitons, skyrmions, and merons, may be much less susceptible to fluctuations, owing to topological constraints, while also being controllable with low current densities. Here, we present the first evidence for soliton/soliton and soliton/antisoliton domain walls in the hexagonal chiral magnet MnNbS that respond asymmetrically to magnetic fields and exhibit pair-annihilation. This is important because it suggests the possibility of controlling the occurrence of soliton pairs and the use of small fields or small currents to control nanoscopic magnetic domains. Specifically, our data suggest that either soliton/soliton or soliton/antisoliton pairs can be stabilized by tuning the balance between intrinsic exchange interactions and long-range magnetostatics in restricted geometries.
畴壁的控制几乎是所有磁性技术的核心，特别是在信息存储和自旋电子学方面。为提高存储密度而进行的创新性尝试需要克服由于纳米尺度畴的热涨落和加热限制所导致的不稳定性。诸如孤子、斯格明子和磁子等拓扑缺陷，由于拓扑约束，可能对涨落的敏感度要低得多，同时也能用低电流密度进行控制。在此，我们首次给出了在六角手性磁体MnNbS中存在孤子/孤子和孤子/反孤子畴壁的证据，这些畴壁对磁场有不对称响应并表现出对湮灭。这很重要，因为它暗示了控制孤子对出现以及利用小磁场或小电流来控制纳米尺度磁畴的可能性。具体而言，我们的数据表明，通过在受限几何结构中调节本征交换相互作用和长程静磁学之间的平衡，可以使孤子/孤子或孤子/反孤子对稳定下来。
