Future applications of antiferromagnets (AFs) in many spintronics devices rely on the precise manipulation of domain walls. The conventional approach using static magnetic fields is inefficient due to the low susceptibility of AFs. Recently proposed electrical manipulation with spin-orbit torques is restricted to metals with a specific crystal structure.
Here we propose an alternative, broadly applicable approach: using asymmetric magnetic field pulses to induce controlled ratchet motion of AF domain walls.
The efficiency of this approach is based on three peculiarities of AF dynamics. First, a time-dependent magnetic field couples with an AF order parameter stronger than a static magnetic field, which leads to higher mobility of the domain walls. Second, the rate of change of the magnetic field couples with the spatial variation of the AF order parameter inside the domain and this enables synchronous motion of multiple domain walls with the same structure. Third, tailored asymmetric field pulses in combination with static friction can prevent backward motion of domain walls and thus lead to the desired controlled ratchet effect.
The proposed use of an external field, rather than internal spin-orbit torques, avoids any restrictions on size, conductivity, and crystal structure of the AF material.
We believe that our approach paves a way for the development of new AF-based devices based on controlled motion of AF domain walls.
Tailoring Exchange Couplings in Magnetic Topological Insulator/Antiferromagnet Heterostructures
磁性拓扑绝缘体，如Cr掺杂的（Bi，Sb）2 Te 3，为实现多功能时间反演破磁物理提供了一个平台。通过在反铁磁CrSb中构建Néel有序异质结构和在Cr掺杂的（Bi，Sb）2 Te 3中构建磁拓扑有序异质结构，实现了可以通过人工结构工程定制的界面磁现象.通过故意的异质结构和超晶格的几何设计，我们证明了反铁磁交换耦合在操纵的拓扑表面大量狄拉克费米子的磁性。这项工作为拓扑绝缘体与反铁磁材料的结合提供了一个新的框架，并为无耗散拓扑反铁磁自旋电子学开辟了新的途径。
Spin-orbit torques in locally and globally non-centrosymmetric crystals: Antiferromagnets and ferromagnets
阻碍反铁磁体实际应用的主要障碍之一是难以操纵磁序参量。最近，根据理论预测[J. J. Eleleznovel et al.，PRL 113，157201（2014）]，已经证明了反铁磁体中磁矩的电切换[P. Wadley等人，Science 351，587（2016）]。这种转变是由于所谓的自旋轨道力矩，这在铁磁体中已经得到了广泛的研究。在这种现象中，电流引起了与有序局部矩耦合的非平衡自旋极化交换，从而对序参量施加了转矩。在这里，我们给出了一个一般的系统分析的自旋轨道力矩的对称性在本地和全球非中心对称的晶体。我们研究的对称性时，允许一个非零的扭矩，当是有效的扭矩，其依赖于所施加的电流方向和方向的磁矩。为了比较，我们考虑反铁磁和铁磁订单。在两个有代表性的模型晶体中，我们进行微观计算的自旋-轨道扭矩，以说明其对称性，并突出条件下，自旋-轨道扭矩可以有效地操纵反铁磁力矩。
Prediction of induced magnetism in 2D Ti$_2$C based MXene by manipulating the mixed surface functionalization and metal substitution computed by xTB model Hamiltonian of the DFTB method
All-optical control of antiferromagnetic domains via an inverse optical magnetoelectric effect
RIKEN Center for Emergent Matter Science (CEMS)（RIKEN 新兴物质科学中心）；Institut für Festkörperforschung（固体研究所）；Department of Advanced Materials Science, The University of Tokyo（东京大学先进材料科学系）；Center for Electronic Correlations and Magnetism, University of Augsburg（奥格斯堡大学电子关联与磁性中心）；Tokyo College and department of Applied Physics, The University of Tokyo（东京大学东京学院与应用物理系）
Sub-spin-flop switching of a fully compensated antiferromagnet by magnetic field
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所凝聚态物理国家实验室）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；International Center for Quantum Materials, School of Physics, Peking University（北京大学物理学院量子材料科学中心）
Field-induced Topological Hall effect in antiferromagnetic axion insulator candidate EuIn$_2$As$_2$
磁性拓扑材料因其潜在的实现各种新量子现象的能力而引起人们的极大关注。EuIn $_2$ As $_2$最近在理论上被认为是期待已久的本征反铁磁体轴子绝缘体。然而，在这种材料中的拓扑状态引起的输运性质的实验研究是稀缺的。在本文中，我们进行了详细的磁阻（MR）和霍尔测量来研究这种材料的磁输运性质。我们发现，运输强烈影响的自旋配置的Eu时刻从伴随的变化的场依赖性的MR和低于Néel温度的磁化强度。最重要的是，观察到异常霍尔效应（AHE）和大的拓扑霍尔效应（THE）。我们认为AHE起源于螺旋自旋结构引起的非零净Berry曲率，而THE归因于外磁场诱导EuIn $_2$ As $_2$形成的具有有限标量自旋手征的非共面自旋织构.我们的研究提供了一个平台，以了解电子能带的拓扑结构和场致磁结构之间的相互作用对磁电输运性质的影响。此外，我们的观测结果还为通过调控EuIn $_2$ As $_2$的磁态实现轴子绝缘体态和高阶拓扑绝缘体态提供了线索.
Manipulating Spin-Lattice Coupling in Layered Magnetic Topological Insulator Heterostructure $via$ Interface Engineering
Indian Association for the Cultivation of Science（印度科学文化研究所）；University of Maine（缅因大学）；Bose Institute（博斯研究所）；UGC-DAE Consortium for Scientific Research, Indore Centre（UGC-DAE科学研究联盟印多尔中心）
Alignment-Dependent Gapless Chiral Split Magnons in Altermagnetic Domain Walls
School of Physics and State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China（电子科技大学物理科学与技术学院及电子薄膜与集成器件国家重点实验室）
