Spatial, momentum and energy separation of electronic spins in condensed matter systems guides the development of novel devices where spin-polarized current is generated and manipulated. Recent attention on a set of previously overlooked symmetry operations in magnetic materials leads to the emergence of a new type of spin splitting, enabling giant and momentum-dependent spin polarization of energy bands on selected antiferromagnets. Despite the ever-growing theoretical predictions, the direct spectroscopic proof of such spin splitting is still lacking. Here, we provide solid spectroscopic and computational evidence for the existence of such materials. In the noncoplanar antiferromagnet MnTe$_2$, the in-plane components of spin are found to be antisymmetric about the high-symmetry planes of the Brillouin zone, comprising a plaid-like spin texture in the antiferromagnetic (AFM) ground state. Such an unconventional spin pattern, further found to diminish at the high-temperature paramagnetic state, stems from the intrinsic AFM order instead of spin-orbit coupling (SOC). Our finding demonstrates a new type of quadratic spin texture induced by time-reversal breaking, placing AFM spintronics on a firm basis and paving the way for studying exotic quantum phenomena in related materials.
Plaid-Like Spin Splitting and Chirality of Magnon Bands in Antiferromagnetic MnTe$_2$
Sejong University（世宗大学）；Korea Advanced Institute of Science and Technology (KAIST)（韩国科学技术院）；Sungkyunkwan University（成均馆大学）；Institute of Physics, Academia Sinica（中央研究院物理研究所）
Néel-order-dependent transverse transport in noncoplanar antiferromagnet $\text{MnTe}_{2}$
Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology（北京理工大学 光电量子架构与测量教育部重点实验室 物理学院）；International Center for Quantum Materials, Beijing Institute of Technology（北京理工大学 国际量子材料中心）
Emergent Noncoplanar Spin Chirality through Magnetic and Nonmagnetic Substitution in the Kagome Antiferromagnet Mn$_3$Sn
S. N. Bose National Centre for Basic Sciences（S.N. 玻色基础科学国家中心）；Ben-Gurion University of the Negev（内盖夫本-古里安大学）；Indian Institute of Science Education and Research Bhopal（印度科学教育与研究学院博帕尔分校）；Indian Institute of Technology Tirupati（印度理工学院提鲁帕蒂分校）
Altermagnetism, ARPES, symmetry, non-relativistic band splitting
Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences（中国科学院上海微系统与信息技术研究所）；University of Chinese Academy of Sciences（中国科学院大学）；National Synchrotron Radiation Laboratory and School of Nuclear Science and Technology, University of Science and Technology of China（中国科学技术大学核科学与技术学院及国家同步辐射实验室）；Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute（上海先进应用研究院上海同步辐射光源）
Signatures of a gearwheel quantum spin liquid in a spin-$\frac{1}{2}$ pyrochlore molybdate Heisenberg antiferromagnet
我们从理论上研究了最近合成的Lu $_2$ Mo $_2$ O $_5$ N $_2$材料的低温相，这是一种非常罕见的$S=1/2$三维烧绿石海森堡反铁磁体的实现，其中Mo $^{5+}$是$S=1/2$磁性物种。尽管居里-外斯温度（$Θ_{\rm CW}$）为$-121(1)$ K，但实验没有发现磁有序$or$自旋冻结到$T^*\approx0.5$ K的特征。利用密度泛函理论，我们发现，该化合物是很好地描述了海森堡模型与交换参数的第三个最近的邻居。通过赝费米子泛函重整化群方法的分析，这个模型揭示了顺磁行为的温度至少$T=|Θ_{\rm CW}|/100$，在暗示可能的三维量子自旋液体的实验结果一致。在倒易空间中的自旋磁化率分布显示动量依赖的功能，形成一个"齿轮"的模式，表征什么可以被视为一个熔融版本的手性noncoplanar无公度螺旋秩序下的量子涨落的作用。我们计算的倒易空间磁化率图提供了基准，为未来的中子散射实验上的单晶Lu $_2$ Mo $_2$ O $_5$ N $_2$。
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.
Tunable chiral and nematic states in the triple-Q antiferromagnet Co$_{1/3}$TaS$_2$
National High Magnetic Field Laboratory, Los Alamos National Lab（国家高磁场实验室，洛斯阿拉莫斯国家实验室）；Materials Science and Technology Division, Oak Ridge National Laboratory（橡树岭国家实验室材料科学与技术部）；Department of Physics and Astronomy, Seoul National University（首尔大学物理与天文学系）；Department of Physics and Astronomy, University of Tennessee, Knoxville（田纳西大学诺克斯维尔分校物理与天文学系）；Shull Wollan Center—A Joint Institute for Neutron Sciences, Oak Ridge National Laboratory（橡树岭国家实验室舒尔-沃兰中子科学联合研究所）；Institute of Applied Physics, Seoul National University（首尔大学应用物理研究所）
