The spontaneous Hall effect, corresponding to a zero-field anomalous Hall effect (AHE), is induced by symmetry breaking associated with ferromagnetism. Studies in recent years, however, have revealed that antiferromagnetic (AFM) states characterized by magnetic point groups that allow ferromagnetism can also break the relevant symmetries and induce AHE without a large net magnetization. Here, we report that the AFM system Ce2PtGe6 exhibits a pronounced spontaneous Hall effect. Single-crystal neutron scattering experiments demonstrate that Ce2PtGe6 exhibits a collinear AFM structure with a propagation vector q=0. The small net magnetization of ∼10−3μB/Ce indicates that the observed AHE arises from symmetry breaking inherent to its AFM structure. The anomalous Hall conductivity (AHC) reaches 300Ω−1cm−1, which exceeds the intrinsic AHC of related compounds such as Ce2CuGe6 and Ce2PdGe6. This large AHC, most likely attributed to the large spin-orbit coupling of the Pt atoms, provides a platform for understanding the interplay between the Berry curvatures and localized f-moments with an AFM configuration.
@article{arxiv.2604.12360,
title = {Large spontaneous Hall effect arising from collinear antiferromagnetism in Ce$_2$PtGe$_6$},
author = {Hayata Matsuda and Ruo Hibino and Chihiro Tabata and Koji Kaneko and Nonoka Higa and Takahiro Onimaru and Hiroto Tanaka and Hideki Tou and Hitoshi Sugawara and Junichi Hayashi and Keiki Takeda and Hisashi Kotegawa},
journal= {arXiv preprint arXiv:2604.12360},
year = {2026}
}