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arXiv · 2608.27025

Intrinsic anomalous Hall response in the bilayer kagome ferromagnet Co$_3$Sn

Yuqi Qin·Soumya Sankar·Xingkai Cheng·Yifan Jiang·Shiming Lei·Junwei Liu·Berthold Jäck
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Abstract

Transition-metal kagome magnets provide a rich platform for investigating the interplay between layer stacking, magnetic order, and band topology. Here, we report the molecular beam epitaxy and experimental investigation of high-quality thin films of the kagome metal Co$_3$Sn, which has not been synthesized in bulk form yet. Structural and chemical analyses confirm a hexagonal lattice structure ($P6_3/mmc$) composed of direct A-B stacked Co$_3$Sn kagome bilayers. Magnetometry reveals robust easy-plane ferromagnetism with a Curie temperature exceeding $300\,\text{K}$. Magneto-transport measurements demonstrate metallic behavior (carrier density $n\approx5.01\times10^{22}\,\text{cm}^{-3}$) alongside a temperature-independent anomalous Hall conductivity of $σ_{\rm AHE}\approx90\,Ω^{-1}\cdot{\rm cm}^{-1}$, extending from $2\,\text{K}$ up to room temperature. Results from first-principles density functional theory calculations attribute this anomalous Hall response to intrinsic Berry curvature hotspots near the Fermi level in the spin-split band structure. Our results establish Co$_3$Sn as a room-temperature kagome ferromagnet and highlight the impact of the layer stacking sequence on the material properties of kagome metals from the CoSn family.

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Yuqi Qin, Soumya Sankar, Xingkai Cheng, Yifan Jiang, Shiming Lei, Junwei Liu, Berthold Jäck. 2026-08-27. Intrinsic anomalous Hall response in the bilayer kagome ferromagnet Co$_3$Sn. https://arxiv.org/abs/2608.27025

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