Giant anomalous Hall effect in a ferromagnetic Kagomé-lattice semimetal

By Enke Liu, Yan Sun, L. Müchler, Aili Sun, L. Jiao, Shuo Yang, Defa Liu, A. Liang, Qiunan Xu, Johannes Kroder and 11 more. Nature Physics, 2017

1,001 citations recorded by the source corpus.

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 topological quantum 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 considerably enhanced Berry curvature from its band structure, the anomalous Hall conductivity and the anomalous Hall angle simultaneously reach 1,130 Ω−1 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. Electrical transport measurements reveal that Co3Sn2S2 is probably a magnetic Weyl semimetal, and hosts the highest simultaneous anomalous Hall conductivity and anomalous Hall angle. This is driven by the strong Berry curvature near the Weyl points.

Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/9cd2d960d5bd1448057e6db92cfa11bb520a1a1c

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In Atomic and Molecular Physics, and Optics

1. Heng Gao
2. Youngkuk Kim
3. J. Venderbos
4. Andrew M. Rappe

In Condensed Matter Physics

1. Heng Gao
2. Youngkuk Kim
3. J. Venderbos
4. Andrew M. Rappe

In Materials Chemistry

1. Heng Gao
2. Youngkuk Kim
3. J. Venderbos
4. Andrew M. Rappe

Citations in the corpus

• Topological Semimetals from First Principles (2018, background): “These magnetic Weyl semimetals exhibit giant anomalous Hall effect in experiment (85, 86, 87, 88), which provides strong evidence for the existence of Weyl points.”