标题： 单层交替磁体的化学设计 显示英文标题

标题： Chemical design of monolayer altermagnets

摘要： 晶体对称性配对的自旋-动量锁定（CSML）源于反铁磁体中不同磁亚晶格之间的固有晶体对称性，使得许多奇特的自旋电子学特性成为可能，例如非常规压磁效应和非共线自旋电流。 然而，单层反铁磁体的缺乏限制了对维度受限现象以及纳米结构器件应用的进一步探索。 在这里，我们提出了一般性的化学设计原理，这些原理受到层状反铁磁体V$_2$(Se,Te)$_2$O 的亚晶格对称性的启发，通过保持对称性的结构修饰和价态适应性化学替代实现。 总共构建了四个结构框架下的2600个候选材料，包括M$_2$A$_2$B$_{1,0}$及其Janus衍生物。 高通量计算识别出670种具有Néel有序基态的潜在反铁磁体，其中91种表现出CSML狄拉克锥，能够实现自旋极化的超快传输。 这些材料还具有不同的基态磁序，并展现出从半导体、金属、半金属到狄拉克半金属的多样的电子行为。 这项工作不仅揭示了丰富的单层反铁磁体，还建立了一个合理的设计原则，为在原子级薄系统中探索受限磁性和自旋电子学打开了大门。 显示英文摘要

摘要： The crystal-symmetry-paired spin-momentum locking (CSML) arisen from the intrinsic crystal symmetry connecting different magnetic sublattices in altermagnets enables many exotic spintronics properties such as unconventional piezomagnetism and noncollinear spin current. However, the shortage of monolayer altermagnets restricts further exploration of dimensionally confined phenomena and applications of nanostructured devices. Here, we propose general chemical design principles inspired by sublattice symmetry of layered altermagnet V$_2$(Se,Te)$_2$O through symmetry-preserving structural modification and valence-adaptive chemical substitutions. In total, we construct 2600 candidates across four structural frameworks, M$_2$A$_2$B$_{1,0}$ and their Janus derivatives. High-throughput calculations identify 670 potential altermagnets with N\'eel-ordered ground states, among which 91 ones exhibiting CSML Dirac cones that enable spin-polarized ultra-fast transport. These materials also feature different ground-state magnetic orderings and demonstrate diverse electronic behaviors, ranging from semiconductors, metals, half-metals, to Dirac semimetals. This work not only reveals abundant monolayer altermagnets, but also establishes a rational principle for their design, opening gates for exploration of confined magnetism and spintronics in atomically thin systems.