二维交替磁体基硫族卤化物的谷与自旋依赖的电子及输运性质
Valley- and Spin-Dependent Electronic and Transport Properties of Two-Dimensional Altermagnetic Titanium-Based Chalcogenide Halides
- Northwest University（西北大学）
- Shaanxi Key Laboratory for Theoretical Physics Frontiers（陕西省理论物理前沿重点实验室）
- Peng Huanwu Center for Fundamental Theory（彭桓武基础理论研究中心）
- Fundamental Discipline Research Center for Quantum Science and Technology of Shaanxi Province（陕西省量子科学与技术基础学科研究中心）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文识别Ti₂X₂Y单层材料为新型二维交替磁体谷材料，揭示其应变调控的谷极化、自旋电流及相关效应，为二维交替磁体的自旋谷相关现象研究提供多功能平台。
AI中文摘要：
交替磁体（AMs）兼具完全补偿的磁化强度与动量依赖的自旋分裂，但具备优异谷特性的本征交替磁体材料仍十分稀缺。本文中，我们确定单层钛基硫族卤化物Ti₂X₂Y（X=F、Cl、Br、I；Y=O、S、Se、Te）为一类新型二维交替磁体谷材料。这些单层材料展现出稳定的d波交替磁序、半导体带隙及显著的自旋极化谷特性。我们表明，单轴应变可打破谷简并，诱导巨谷极化及可调谐的压磁响应；面内电场可产生非共线自旋电流；而自旋轨道耦合则会引发反常霍尔效应、谷选择性线性二色性及磁光克尔效应。这些发现确立了Ti₂X₂Y单层材料作为探索二维交替磁体中自旋与谷依赖的电子、光学及输运现象的多功能平台。
英文摘要：
Altermagnets (AMs) combine fully compensated magnetization with momentum-dependent spin splitting, yet intrinsic altermagnetic materials exhibiting exceptional valley characteristics remain scarce. Here, we identify monolayer titanium-based chalcogenide halides, Ti$_2X_2Y$ ($X$ = F, Cl, Br, I; $Y$ = O, S, Se, Te), as a new family of two-dimensional altermagnetic valley materials. These monolayers exhibit robust $d$-wave altermagnetic order, semiconducting band gaps, and pronounced spin-polarized valley characteristics. We show that uniaxial strain breaks the valley degeneracy, inducing giant valley polarization together with a tunable piezomagnetic response. An in-plane electric field generates noncollinear spin currents, while spin--orbit coupling gives rise to the anomalous Hall effect, valley-selective linear dichroism, and the magneto-optical Kerr effect. These findings establish Ti$_2X_2Y$ monolayers as a versatile platform for exploring spin- and valley-dependent electronic, optical, and transport phenomena in two-dimensional altermagnets.
