载流子补偿反铁磁半金属NiS中的狄拉克拓扑、反常霍尔响应和巨磁电阻
Dirac topology, anomalous Hall response, and giant magnetoresistance in carrier-compensated altermagnetic semimetal NiS
浏览论文内容
中文总结 AI 辅助
研究通过多种理论方法确定六角形NiS为补偿型3d反铁磁半金属，其拓扑、磁性和晶格动力学相互交织。该材料有大的各向异性本征自旋霍尔电导率等特性，还揭示了其磁性相互作用，为相关化合物多功能量子响应提供设计原则。
中文摘要 AI 辅助
我们结合第一性原理密度泛函理论、贝里曲率分析、半经典玻尔兹曼输运和原子自旋动力学，确定六角形NiS为一种补偿型3d反铁磁半金属，其中拓扑、磁性和晶格动力学内在交织。NiAs晶格的旋转陪集对称性产生反铁磁特有的动量依赖自旋分裂。通过自旋轨道耦合，带隙狄拉克型交叉产生强烈的贝里曲率热点和近补偿的电子-空穴口袋。这导致了与几种4d、5d金属相当的大的各向异性本征自旋霍尔电导率，尽管净磁化强度为零但有对称允许的反常霍尔响应，以及超过10000%的非饱和磁电阻。在磁性方面，交换张量的第一性原理确定揭示了主导的长程超交换和可观的各向异性相互作用，定量再现了实验尼尔温度。我们的结果确定NiS为一个模型3d平台，其中载流子补偿、反铁磁对称性、贝里曲率驱动的输运和晶格敏感磁性在单一对称框架内共存，为相关过渡金属化合物中的多功能量子响应提供了设计原则。
英文摘要
We combine first-principles density-functional theory, Berry-curvature analysis, semiclassical Boltzmann transport, and atomistic spin dynamics to establish hexagonal NiS as a compensated 3d altermagnetic semimetal in which topology, magnetism, and lattice dynamics are intrinsically intertwined. The rotational coset symmetry of the NiAs lattice produces momentum-dependent spin splitting characteristic of altermagnetism. With spin-orbit coupling, gapped Dirac-like crossings generate intense Berry-curvature hot spots and nearly compensated electron-hole pockets. This leads to a large and anisotropic intrinsic spin Hall conductivity comparable to that of several 4d, 5d metals, a symmetry-allowed anomalous Hall response despite zero net magnetization, and nonsaturating magnetoresistance exceeding 10000 percent. On the magnetic side, first-principles determination of the exchange tensor reveals dominant long-range superexchange and sizable anisotropic interactions, quantitatively reproducing the experimental Neel temperature. Our results identify NiS as a model 3d platform in which carrier compensation, altermagnetic symmetry, Berry-curvature driven transport, and lattice-sensitive magnetism coexist within a single symmetry framework, offering a design principle for multi-functional quantum responses in correlated transition-metal compounds.
