Magnetic Weyl semimetals with broken time-reversal symmetry are expected to generate strong intrinsic anomalous Hall effects, due to their large Berry curvature. Here, we report a magnetic Weyl semimetal candidate Co3Sn2S2 with a quasi-two-dimensional crystal structure consisting of stacked Kagome lattices. This lattice provides an excellent platform for hosting exotic quantum topological states. We observe a negative magnetoresistance that is consistent with the chiral anomaly expected from the presence of Weyl fermions close to the Fermi level. The anomalous Hall conductivity is robust against both increased temperature and charge conductivity, which corroborates the intrinsic Berry-curvature mechanism in momentum space. Owing to the low carrier density in this material and the significantly enhanced Berry curvature from its band structure, the anomalous Hall conductivity and the anomalous Hall angle simultaneously reach 1130 S cm-1 and 20%, respectively, an order of magnitude larger than typical magnetic systems. Combining the Kagome-lattice structure and the long-range out-of-plane ferromagnetic order of Co3Sn2S2, we expect that this material is an excellent candidate for observation of the quantum anomalous Hall state in the two-dimensional limit.
@article{arxiv.1712.06722,
title = {Giant anomalous Hall effect in a ferromagnetic Kagome-lattice semimetal},
author = {Enke Liu and Yan Sun and Nitesh Kumar and Lukas Meuchler and Aili Sun and Lin Jiao and Shuo-Ying Yang and Defa Liu and Aiji Liang and Qiunan Xu and Johannes Kroder and Vicky Seuss and Horst Borrmann and Chandra Shekhar and Zhaosheng Wang and Chuanying Xi and Wenhong Wang and Walter Schnelle and Steffen Wirth and Yulin Chen and Sebastian T. B. Goennenwein and Claudia Felser},
journal= {arXiv preprint arXiv:1712.06722},
year = {2019}
}