AI 中文总结
研究聚焦于AgCrP₂S₆范德瓦尔斯磁体，结合计算与分析，发现二维晶格中反铁磁链可实现交变磁性，面外电场能调控自旋分裂，通过紧束缚模型解释相关行为，还证明Janus替代及铁电界面等也能实现特定自旋纹理与带控制，为准一维反铁磁体用于交变磁性奠定基础。
AI 中文摘要
交变磁性是一种共线磁态，在完全补偿材料中具有与动量相关的自旋分裂。虽然在三维或二维交换相互作用系统中已被广泛研究，但在准一维磁体中的扩展几乎未被探索。以实验确定的AgCrP₂S₆范德瓦尔斯磁体为重点，证明二维晶格中嵌入的反铁磁链是实现交变磁性的一般途径。结合第一性原理计算和自旋空间群分析，表明面外对称性破缺可产生非相对论性d波自旋分裂。外部面外电场验证了该机制，诱导分裂随场强线性增加且随场方向改变符号。通过构建有效紧束缚模型解释了这种行为，该模型将交变磁响应与各向异性第三近邻链间跳跃联系起来。此外，表明Janus替代也会诱导d波自旋纹理，与CuInP₂S₆的铁电界面在完全补偿亚铁磁态中实现极化控制的自旋分裂带。结果确立了准一维反铁磁体作为交变磁性的构建块。
英文摘要
Altermagnetism is a collinear magnetic state characterized by momentum-dependent spin splitting in fully compensated materials. While widely investigated in systems governed by three- or two-dimensional exchange interactions, its extension to quasi-one-dimensional magnets remains almost unexplored. Focusing on the experimentally established AgCrP$_2$S$_6$ van der Waals magnet, we demonstrate that antiferromagnetic chains embedded in a two-dimensional lattice provide a general route to altermagnetism. Combining first-principles calculations and spin-space-group analysis, we show that out-of-plane symmetry breaking can generate a nonrelativistic d-wave spin splitting. An external out-of-plane electric field validates this mechanism, where the induced splitting increases linearly with field strength and reverses sign with field direction. We rationalize such behaviour by constructing an effective tight-binding model, which links the altermagnetic response to anisotropic third-neighbor interchain hoppings. Additionally, we show that Janus substitution also induces a d-wave spin texture, while ferroelectric interfacing with CuInP$_2$S$_6$ enables polarization-controlled spin-split bands in a fully compensated ferrimagnetic state. Our results establish quasi-one-dimensional antiferromagnets as building blocks for altermagnetism.
