论文标题
具有伪级电子自旋的Altermagnetism和磁性基团
Altermagnetism and magnetic groups with pseudoscalar electron spin
论文作者
论文摘要
我们修改了现有的群体理论方法，以治疗具有完美翻译不变性的非层次性共线磁系统。我们表明，这些系统的完整对称组，这些组包含旋转和配置空间中具有独立旋转的元件（自旋组），可以用由旋转仅作用于位置向量的旋转的元素来代替。这种降低是从电子自旋的修改转换特性中进行的，在被考虑的系统中，在空间操作时，在被考虑的系统中有效地变成了伪级数量不变，但由于反对称性的操作而改变了其符号。我们引入了相关磁点基团的单一表示，并将其用于从抗磁磁性诱导的抗铁磁性诱导的电子带的旋转分裂的角度分类，而在布里渊区中心附近的电子带。我们证明，最近揭示的不同的Altermagnetic类以独特的方式对应于所有非平凡的磁性LAUE类别，即仅与空间旋转结合使用反对称性的LAUE组。发现其中四个laue类与非零自旋电导率兼容。随后对简单模型的检查使我们能够简要解决负责实际系统中旋转分裂的物理机制。
We revise existing group-theoretical approaches for a treatment of nonrelativistic collinear magnetic systems with perfect translation invariance. We show that full symmetry groups of these systems, which contain elements with independent rotations in the spin and configuration spaces (spin groups), can be replaced by magnetic groups consisting of elements with rotations acting only on position vectors. This reduction follows from modified transformation properties of electron spin, which in the considered systems becomes effectively a pseudoscalar quantity remaining unchanged upon spatial operations but changing its sign due to an operation of antisymmetry. We introduce a unitary representation of the relevant magnetic point groups and use it for a classification of collinear magnets from the viewpoint of antiferromagnetism-induced spin splitting of electron bands near the center of Brillouin zone. We prove that the recently revealed different altermagnetic classes correspond in a unique way to all nontrivial magnetic Laue classes, i.e., to the Laue groups containing the operation of antisymmetry only in combination with a spatial rotation. Four of these Laue classes are found compatible with a nonzero spin conductivity. Subsequent inspection of a simple model allows us to address briefly the physical mechanisms responsible for the spin splitting in real systems.
