Yuan Lin-Ding, Zhang Xiuwen, Acosta Carlos Mera, Zunger Alex
Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO, 80309, USA.
Center for Natural and Human Sciences, Federal University of ABC, Santo Andre, São Paulo, Brazil.
Nat Commun. 2023 Aug 31;14(1):5301. doi: 10.1038/s41467-023-40877-8.
Many textbook physical effects in crystals are enabled by some specific symmetries. In contrast to such 'apparent effects', 'hidden effect X' refers to the general condition where the nominal global system symmetry would disallow the effect X, whereas the symmetry of local sectors within the crystal would enable effect X. Known examples include the hidden Rashba and/or hidden Dresselhaus spin polarization that require spin-orbit coupling, but unlike their apparent counterparts are demonstrated to exist in non-magnetic systems even in inversion-symmetric crystals. Here, we discuss hidden spin polarization effect in collinear antiferromagnets without the requirement for spin-orbit coupling (SOC). Symmetry analysis suggests that antiferromagnets hosting such effect can be classified into six types depending on the global vs local symmetry. We identify which of the possible collinear antiferromagnetic compounds will harbor such hidden polarization and validate these symmetry enabling predictions with first-principles density functional calculations for several representative compounds. This will boost the theoretical and experimental efforts in finding new spin-polarized materials.
晶体中的许多教科书式的物理效应是由某些特定对称性促成的。与这种“表观效应”不同，“隐藏效应X”指的是这样一种一般情况：名义上的全局系统对称性会禁止效应X，而晶体中局部区域的对称性却会使效应X成为可能。已知的例子包括需要自旋轨道耦合的隐藏 Rashba 和/或隐藏 Dresselhaus 自旋极化，但与它们的表观对应物不同，已证明即使在具有反演对称性的晶体中的非磁性系统中也存在这种极化。在这里，我们讨论共线反铁磁体中无需自旋轨道耦合（SOC）的隐藏自旋极化效应。对称性分析表明，具有这种效应的反铁磁体根据全局与局部对称性可分为六种类型。我们确定哪些可能的共线反铁磁化合物会具有这种隐藏极化，并通过对几种代表性化合物进行第一性原理密度泛函计算来验证这些对称性促成的预测。这将推动寻找新型自旋极化材料的理论和实验工作。
