arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新，休息一下吧，周末愉快~~
arXiv 1801.02560cond-mat.mtrl-sci
收藏

室温下α- Fe2O3/Co异质结中磁涡旋对的观测

Observation of magnetic vortex pairs at room temperature in a planar α-Fe2O3/Co heterostructure

F. P. Chmiel, N. Waterfield Price, R. D. Johnson, A. D. Lamirand, J. Schad, G. van der Laan, D. T. Harris, J. Irwin, M. S. Rzchowski, C. -B. Eom, P. G. Radaelli

备注：
16 pages, 4 figures
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

涡流是最简单的拓扑结构之一，当流场围绕一维核“旋转”时就会出现。它们在物理学的许多分支中无处不在，从流体动力学到超导性和超流性，甚至被一些粒子相互作用的统一理论所预测，它们可能解释今天宇宙中看到的一些最大尺度的结构。在结晶状态下，涡旋的形成是罕见的，因为它通常受到长程相互作用的阻碍：在铁性材料（铁磁和铁电）中，只有当偶极-偶极相互作用的影响被纳米尺度的限制所改变时，或者当与涡旋相关的参数不直接与应变耦合时，才能观察到涡旋。在这里，我们提出的反铁磁（AFM）赤铁矿（$α$ -Fe $_2$ O $_3$）外延薄膜中的一种新形式的涡旋的发现，其中的主要旋转参数是交错磁化。值得注意的是，具有与$α$相同的涡度和缠绕数的铁磁（FM）拓扑物体-Fe $_2$ O $_3$涡通过界面交换被压印到超薄Co铁磁覆层上。我们的数据表明，铁磁涡旋可能是merons（半skyrmions，携带出平面的核心磁化），并表明，涡旋/meron对可以操纵的应用程序的平面内的磁场，H $_{\parallel}$，引起大规模的涡旋-反涡旋湮灭。

英文摘要：

Vortices are among the simplest topological structures, and occur whenever a flow field `whirls' around a one-dimensional core. They are ubiquitous to many branches of physics, from fluid dynamics to superconductivity and superfluidity, and are even predicted by some unified theories of particle interactions, where they might explain some of the largest-scale structures seen in today's Universe. In the crystalline state, vortex formation is rare, since it is generally hampered by long-range interactions: in ferroic materials (ferromagnetic and ferroelectric), vortices are only observed when the effects of the dipole-dipole interaction is modified by confinement at the nanoscale, or when the parameter associated with the vorticity does not couple directly with strain. Here, we present the discovery of a novel form of vortices in antiferromagnetic (AFM) hematite ($α$-Fe$_2$O$_3$) epitaxial films, in which the primary whirling parameter is the staggered magnetisation. Remarkably, ferromagnetic (FM) topological objects with the same vorticity and winding number of the $α$-Fe$_2$O$_3$ vortices are imprinted onto an ultra-thin Co ferromagnetic over-layer by interfacial exchange. Our data suggest that the ferromagnetic vortices may be merons (half-skyrmions, carrying an out-of-plane core magnetisation), and indicate that the vortex/meron pairs can be manipulated by the application of an in-plane magnetic field, H$_{\parallel}$, giving rise to large-scale vortex-antivortex annihilation.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑