Broken inversion symmetry in combination with the spin-orbit interaction generates a finite Dzyaloshinskii-Moriya interaction (DMI), which can induce noncollinear spin textures of chiral nature. The DMI is characterized by an interaction vector whose magnitude, direction and symmetries are crucial to determine the stability of various spin textures, such as skyrmions and spin spirals. The DMI can be measured from the nonreciprocity of spin waves in ferromagnets, which can be probed via inelastic scattering experiments. In a ferromagnet, the DMI can modify the spin-wave dispersion, moving its minimum away from the $Γ$ point. Spin waves propagating with opposite wavevectors are then characterized by different group velocities, energies and lifetimes, defining their nonreciprocity. Here, we address the case of complex spin textures, where the manifestation of DMI-induced chiral asymmetries remains to be explored. We discuss such nonreciprocal effects and propose ways of accessing the magnitude and direction of the DMI vectors in the context of spin-polarized or spin-resolved inelastic scattering experiments. We show that only when a periodic magnetic system has finite net magnetization, that is, when the vector sum of all magnetic moments is nonzero, can it present a total nonreciprocal spin-wave spectrum. However, even zero-net-magnetization systems, such as collinear antiferromagnets and cycloidal spin spirals, can have spin-wave modes that are individually nonreciprocal, while the total spectrum remains reciprocal.
Modelling spin waves in noncollinear antiferromagnets: spin-flop states, spin spirals, skyrmions and antiskyrmions
反铁磁材料中的自旋波在下一代磁振子技术中具有巨大的潜力。然而，它们的性质及其对基态反铁磁结构类型的依赖性仍然是一个悬而未决的问题。在这里，我们研究理论上的自旋波在一维和二维模型系统的重点是非共线反铁磁纹理，如自旋螺旋和相反的拓扑电荷skyrmions。我们特别解决了最近在体反铁磁体$α$ -$\text{Cu}_2\text{V}_2\text{O}_7$中利用非弹性中子散射实验测量的非互易自旋激发[Phys.\修订版本\ Lett. \textbf{119}，047201（2017）]，其中我们帮助表征检测到的自旋波模式的性质。此外，我们讨论了Dzyaloshinskiii-Moriya相互作用如何提高反铁磁物质中自旋波模式的简并度，类似于电子Rashba分裂。本文研究了反铁磁自旋螺旋系统和Skyrmion系统中的自旋波激发，讨论了它们的非弹性散射谱特征。我们证明了在某些反铁磁体中，可以用各向同性的Dzyaloshinskiii-Moriya相互作用获得反克尔米离子。
Magnon chiral damping beyond the Dzyaloshinskii-Moriya interaction
Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau（莱茵兰-普法尔茨技术大学凯泽斯劳滕-兰道分校）；Indian Institute of Technology (Indian School of Mines)（印度理工学院（印度矿业学院））；Uppsala University（乌普萨拉大学）；University of Münster（明斯特大学）
Topological Magnetic Phases and Magnon-Phonon Hybridization in the Presence of Strong Dzyaloshinskii-Moriya Interaction
School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院）；Wilczek Quantum Center, School of Physics and Astronomy, Shanghai Jiao Tong University（上海交大物理与天文学院李政道量子中心）；Shanghai Research Center for Quantum Sciences（上海量子科学研究中心）；Department of Physics, The Chinese University of Hong Kong（香港中文大学物理系）；Institute for Quantum Science and Technology, Shanghai University（上海大学量子科学与技术研究院）；Department of Physics, Shanghai University（上海大学物理系）
Intermediate anomalous Hall states induced by noncollinear spin structure in magnetic topological insulator MnBi2Te4
拓扑结构和磁性的结合是产生奇异量子物质的诱人途径，如量子反常霍尔态、轴子绝缘体和磁性外尔半金属等。MnBi 2 Te 4作为一种内禀磁性拓扑绝缘体，为实现各种拓扑相提供了平台。在这里，我们报告的中间霍尔台阶的磁滞MnBi 2 Te 4，其中四个可区分的磁记忆状态在零磁场被揭示。磁性中间态的门和温度依赖性表明MnBi 2 Te 4中的非共线自旋结构，这可以归因于Dzyaloshinskiii-Moriya相互作用，即强自旋-轨道耦合和表面局部反转对称性破缺的共存。此外，这些多个磁存储器状态可以通过施加设计的磁场脉冲来编程地在彼此之间切换。我们的研究结果提供了新的见解的影响体拓扑结构的磁状态，和多个存储状态应该是有前途的自旋电子器件。
Frustrated out-of-plane Dzyaloshinskii-Moriya interaction and the onset of atomic-scale 3$q$ magnetic textures in 2D Fe$_{3}$GeXTe (X = Te, Se, S) monolayers
Ankara University（安卡拉大学）；Université Grenoble Alpes, CEA, CNRS, Grenoble INP, SPINTEC（格勒诺布尔阿尔卑斯大学、法国原子能和替代能源委员会、法国国家科学研究中心、格勒诺布尔国立理工学院、自旋电子学与自旋存储中心）；The University of Osaka（大阪大学）；Université Grenoble Alpes, CEA, Leti（格勒诺布尔阿尔卑斯大学、法国原子能和替代能源委员会、微电子技术研究实验室）；Institut universitaire de France（法国高等教育研究院）
Exchange-dominated frequency shift of spin-wave nonreciprocal dispersion relation in planar magnetic multilayers
Universidad Católica del Norte（天主教辅仁大学北部分校）；Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research（德累斯顿-罗森多夫亥姆霍兹中心离子束物理与材料研究所）
