发表机构
S. N. Bose National Centre for Basic Sciences; Ben-Gurion University of the Negev; Indian Institute of Science Education and Research Bhopal; Indian Institute of Technology Tirupati（S.N. 玻色基础科学国家中心; 内盖夫本-古里安大学; 印度科学教育与研究学院博帕尔分校; 印度理工学院提鲁帕蒂分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过Cr和Cu替代调控Mn$_3$Sn中的自旋手性，分别增强低温倾斜和诱导自旋重取向，产生拓扑霍尔效应，揭示交换增强与稀释两种调控Berry曲率的路径。
AI 中文摘要
在中心对称磁体中控制非共面自旋织构仍然是实现涌现Berry相现象的核心挑战。在此，我们证明在Mn位点进行磁性（Cr）和非磁性（Cu）替代为在kagome反铁磁体Mn$_3$Sn中工程化自旋手性和拓扑输运提供了不同途径。Cr替代增强了低温自旋倾斜，稳定了致密的非共面织构，从而在低温下产生显著的拓扑霍尔效应（THE）。相比之下，Cu替代驱动了伴随易轴旋转的自旋重取向转变，创建了一个宽温度窗口（150--208 K），在该窗口中竞争性磁各向异性稳定了非共面自旋织构并产生大的THE。同时发生的载流子类型交叉表明底层电子结构重构。这些结果揭示交换增强和交换稀释代表了调控实空间Berry曲率的两种根本不同途径，确立了化学替代作为在kagome反铁磁体中工程化拓扑输运的强大策略。
英文摘要
Controlling noncoplanar spin textures in centrosymmetric magnets remains a central challenge for realizing emergent Berry-phase phenomena. Here, we demonstrate that magnetic (Cr) and nonmagnetic (Cu) substitution at the Mn site provide distinct routes to engineer spin chirality and topological transport in the kagome antiferromagnet Mn$_3$Sn. Cr substitution enhances low-temperature spin canting, stabilizing a dense noncoplanar texture that yields a pronounced topological Hall effect (THE) at low temperatures. In contrast, Cu substitution drives a spin-reorientation transition accompanied by an easy-axis rotation, creating a broad temperature window (150--208 K) where competing magnetic anisotropies stabilize noncoplanar spin textures and generate a large THE. A concurrent carrier-type crossover signals an underlying electronic-structure reconstruction. These results reveal that exchange enhancement and exchange dilution represent two fundamentally different pathways for tuning real-space Berry curvature, establishing chemical substitution as a powerful strategy for engineering topological transport in kagome antiferromagnets.
CommentsAccepted for publication in Materials Today Physics, 35 pages, 8 figures
