Antão Tiago V C, Lado Jose L, Fumega Adolfo O
Department of Applied Physics, Aalto University, 02150 Espoo, Finland.
Nano Lett. 2024 Dec 11;24(49):15767-15773. doi: 10.1021/acs.nanolett.4c04582. Epub 2024 Nov 22.
Twisted magnetic van der Waals materials provide a flexible platform to engineer unconventional magnetism. Here we demonstrate the emergence of electrically tunable topological moiré magnetism in twisted bilayers of the spin-spiral multiferroic NiI. We establish a rich phase diagram featuring uniform spiral phases, a variety of -skyrmion lattices, and nematic spin textures ordered at the moiré scale. The emergence of these phases is driven by the local stacking and the resulting moiré modulated frustration. Notably, when the spin-spiral wavelength is commensurate with the moiré length scale by an integer , multiwalled skyrmions become pinned to the moiré pattern. We show that the strong magnetoelectric coupling displayed by the moiré multiferroic allows electric control of the -skyrmion lattices by an out-of-plane electric field. Our results establish a highly tunable platform for skyrmionics based on twisted van der Waals multiferroics, potentially enabling a new generation of ultrathin topologically protected spintronic devices.
扭曲的磁性范德华材料为研究非常规磁性提供了一个灵活的平台。在此，我们展示了在自旋螺旋多铁性材料NiI的扭曲双层中出现的电可调拓扑莫尔磁性。我们建立了一个丰富的相图，其中包括均匀螺旋相、各种手征斯格明子晶格以及在莫尔尺度上有序的向列自旋纹理。这些相的出现是由局部堆叠和由此产生的莫尔调制挫折驱动的。值得注意的是，当自旋螺旋波长与莫尔长度尺度成整数倍时，多壁斯格明子会被钉扎在莫尔图案上。我们表明，莫尔多铁性材料所表现出的强磁电耦合允许通过面外电场对 手征斯格明子晶格进行电控制。我们的结果基于扭曲的范德华多铁性材料建立了一个高度可调的斯格明子学平台，这有可能促成新一代超薄拓扑保护自旋电子器件的诞生。
