Isolated magnetic skyrmions are stable, topologically protected spin textures that are at the forefront of research interests today due to their potential applications in information technology. A distinct class of skyrmion hosts are rare earth - transition metal (RE-TM) ferrimagnetic materials. To date, the nature and the control of basic traits of skyrmions in these materials are not fully understood. We show that for an archetypal ferrimagnetic material DyCo$_3$ that exhibits a strong perpendicular anisotropy, the ferrimagnetic skyrmion size can be tuned by an external magnetic field. Moreover, by taking advantage of the high spatial resolution of scanning transmission X-ray microscopy (STXM) and utilizing a large x-ray magnetic linear dichroism (XMLD) contrast that occurs naturally at the RE resonant edges, we resolve the nature of the magnetic domain walls of ferrimagnetic skyrmions. We demonstrate that through this method one can easily discriminate between Bloch and Néel type domain walls for each individual skyrmion. For all isolated ferrimagnetic skyrmions, we observe that the domain walls are of Néel-type. This key information is corroborated with results of micromagnetic simulations and allows us to conclude on the nature of the Dzyaloshinskii-Moriya interaction (DMI) which concurs to the stabilisation of skyrmions in this ferrimagnetic system. Establishing that an intrinsic DMI occurs in RE-TM materials will also be beneficial towards a deeper understanding of chiral spin texture control in ferrimagnetic materials.
Orientation-resolved ultrafast spin reorientation dynamics in ferrimagnetic DyCo$_5$
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie（马克斯·玻恩非线性光学和超快光谱学研究所）；Leibniz-Institut für Kristallzüchtung（莱布尼茨晶体生长研究所）；European XFEL（欧洲X射线自由电子激光设施）；Technische Universität Berlin, Institut für Optik und Atomare Physik（柏林工业大学光学与原子物理研究所）
Current-driven dynamics and inhibition of the skyrmion Hall effect of ferrimagnetic skyrmions in GdFeCo films
磁skyrmions旋转的磁性纹理与新的特点，适合未来的自旋电子学和拓扑学的应用。最近的研究证实了Skyrmion在铁磁体中的室温稳定性。然而，这样的铁磁skyrmion显示出不期望的拓扑效应，skyrmion霍尔效应，这导致它们朝向器件边缘的电流驱动运动，其中skyrmion可以容易地被拓扑缺陷湮灭。最近的理论研究已经预测了反铁磁交换耦合skyrmions增强的电流驱动行为。在这里，我们提出了这些skyrmions和它们的电流驱动的动力学在亚铁磁GdFeCo薄膜的稳定。通过利用特定元素的X射线成像，我们发现，在Gd和FeCo子层的skyrmion是反铁磁交换耦合。我们进一步证实了亚铁磁Skyrmion可以以约50 m s-1的速度运动，约化Skyrmion Hall角θSkHE约为20°。我们的研究结果打开了亚铁磁和反铁磁skyrmionics的大门，同时提供了关键的实验证据，最近的理论研究。
Ferrimagnetic Skyrmions in a Tetragonal Mn1.9Co0.1Sb Single Crystal at Room Temperature
Anhui University（安徽大学）；Wuhan University of Technology（武汉理工大学）；High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences（中国科学院合肥物质科学研究院强磁场科学中心）
Magnetic moment orientation and in depth distribution of dysprosium near the surface of DyCo$_{4.6}$ thin films determined by the analysis of their X ray circularly polarized absorption Dy $M_{5}$ spectra
Spin-Hall Topological Hall Effect in Highly Tunable Pt/Ferrimagnetic-Insulator Bilayers
拓扑磁纹理，如skyrmions的电检测目前仅限于导电材料。虽然磁性绝缘体为Skyrmion技术提供了高速和低损耗的关键优势，但它们尚未被电探索。在这里，我们报告了一个突出的拓扑霍尔效应在Pt/Tm $_3$ Fe $_5$ O $_{12}$双层，其中原始的Tm $_3$ Fe $_5$ O $_{12}$外延膜的厚度下降到1.25单位电池允许调谐拓扑霍尔稳定性在很宽的范围内从200到465 K通过原子尺度的厚度控制。虽然Tm $_3$ Fe $_5$ O $_{12}$是绝缘的，我们证明了通过一种新的现象：“自旋霍尔拓扑霍尔效应”（SH-THE），其中界面自旋轨道扭矩允许自旋霍尔效应产生的自旋在Pt中经历独特的拓扑结构的底层skyrmions在Tm $_3$ Fe $_5$ O $_{12}$的拓扑磁纹理的检测。这种新颖的电检测现象为在未来的skyrmion技术中利用大家族的磁性绝缘体铺平了新的道路。
Thermal Evolution of Skyrmions in Synthetic Ferrimagnets of Co/Gd Heterostructure for Topological Spintronic Applications
National Institute of Science Education and Research (NISER)（印度科学教育研究所）；Homi Bhabha National Institute (HBNI)（霍米·巴巴国立大学）；Indian Institute of Science Education and Research (IISER) Mohali（印度科学教育研究学院莫哈利分校）；Durham University（杜伦大学）
Emergence of a spin Hall topological Hall effect in the non-collinear phase of the ferrimagnetic insulator terbium-iron garnet
Institute of Physics, Johannes Gutenberg University Mainz（美因茨约翰内斯·古腾堡大学物理研究所）；Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C-1), Forschungszentrum Jülich GmbH（于利希研究中心格恩斯特·鲁斯卡电子显微与光谱中心（ER-C-1））；Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology（挪威科技大学量子自旋电子学中心）
Anisotropic mesoscale magnetic scattering across the spin-reorientation transition in TbMn6Sn6
Spallation Neutron Source Science Center（散裂中子源科学中心）；Institute of High Energy Physics, Chinese Academy of Sciences (CAS)（中国科学院高能物理研究所）；Guangdong Provincial Key Laboratory of Extreme Conditions（广东省极端条件重点实验室）
Revealing domain wall stability during ultrafast demagnetization
Max Planck Institute for Multidisciplinary Sciences（马克斯·普朗克多学科研究所）；Institute of Physics, University of Augsburg（奥格斯堡大学物理研究所）；School of Electrical Engineering, Tel Aviv University（特拉维夫大学电气工程学院）；th Physical Institute, University of Göttingen（哥廷根大学第四物理研究所）；Radboud University, Institute for Molecules and Materials（拉德堡德大学分子与材料研究所）
