AI 中文总结
本研究通过第一性原理计算，揭示了典型压磁材料CoF₂的两种压磁微观机制，为理解压磁反铁磁体的共性特征提供了关键依据。
AI 中文摘要
金红石结构的CoF₂长期被视为典型压磁材料，近来因其作为无自旋轨道耦合仍具自旋劈裂电子带的反常铁磁体（altermagnet）而重新受到关注。尽管已从磁对称性角度广泛讨论过CoF₂的压磁响应，但其微观起源仍不明确。第一性原理计算揭示了CoF₂中压磁效应的两种不同微观机制：在xy剪切应变下，两个Co位点周围CoF₆八面体的局部体积出现差异，导致两个亚晶格的磁矩不等，进而产生净磁化；与之相反，在yz剪切应变下，压磁响应源于自旋轨道耦合通过Dzyaloshinskii-Moriya相互作用诱导的自旋倾斜。两种不同微观机制的存在可能是压磁反铁磁体的普遍特征。
英文摘要
Rutile-structured CoF$_2$ has long been recognized as a prototypical piezomagnetic material. Recently, it has attracted renewed interest as an altermagnet, exhibiting spin-split electronic bands even in the absence of spin-orbit coupling. Although the piezomagnetic response of CoF$_2$ has been extensively discussed from the viewpoint of magnetic symmetry, its microscopic origin has remained elusive. First-principles calculations reveal two distinct microscopic mechanisms of piezomagnetism in CoF$_2$. Under $xy$ shear strain, the local volumes of the CoF$_6$ octahedra surrounding the two Co sites become different, leading to unequal magnetic moments on the two sublattices and hence a net magnetization. In contrast, under $yz$ shear strain, the piezomagnetic response originates from spin canting induced by the Dzyaloshinskii--Moriya interaction through spin-orbit coupling. The presence of two distinct microscopic mechanisms may be a general feature of piezomagnetic antiferromagnets.
