Kawamura Taiki, Yoshimi Kazuyoshi, Hashimoto Kenichiro, Kobayashi Akito, Misawa Takahiro
Department of Physics, Nagoya University, Nagoya, Aichi 464-8602, Japan.
Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Phys Rev Lett. 2024 Apr 12;132(15):156502. doi: 10.1103/PhysRevLett.132.156502.
The study of the magnetic order has recently been invigorated by the discovery of exotic collinear antiferromagnets with time-reversal symmetry breaking. Examples include altermagnets and compensated ferrimagnets, which show spin splittings of the electronic band structures even at zero net magnetization, leading to several unique transport phenomena, notably spin-current generation. Altermagnets demonstrate anisotropic spin splitting, such as d-wave, in momentum space, whereas compensated ferrimagnets exhibit isotropic spin splitting. However, methods to realize compensated ferrimagnets are limited. Here, we demonstrate a method to realize a fully compensated ferrimagnet with isotropic spin splitting utilizing the dimer structures inherent in organic compounds. Moreover, based on ab initio calculations, we find that this compensated ferrimagnet can be realized in the recently discovered organic compound (EDO-TTF-I){2}ClO{4}. Our findings provide an unprecedented strategy for using the dimer degrees of freedom in organic compounds to realize fully compensated ferrimagnets with colossal spin splitting.
最近，具有时间反演对称性破缺的奇异共线反铁磁体的发现为磁序研究注入了活力。例子包括交替磁体和补偿亚铁磁体，它们即使在净磁化为零时也显示出电子能带结构的自旋分裂，从而导致几种独特的输运现象，特别是自旋电流的产生。交替磁体在动量空间中表现出各向异性自旋分裂，如d波，而补偿亚铁磁体表现出各向同性自旋分裂。然而，实现补偿亚铁磁体的方法有限。在此，我们展示了一种利用有机化合物固有的二聚体结构来实现具有各向同性自旋分裂的完全补偿亚铁磁体的方法。此外，基于从头算计算，我们发现这种补偿亚铁磁体可以在最近发现的有机化合物(EDO-TTF-I)₂ClO₄中实现。我们的发现为利用有机化合物中的二聚体自由度来实现具有巨大自旋分裂的完全补偿亚铁磁体提供了前所未有的策略。
