Bipolarity Induced Gigantic Intrinsic Anomalous Hall Effect in Iterative-Grown Kagome Semimetal Co₃Sn₂S₂ Crystals

As a magnetic Weyl semimetal with broken time-reversal symmetry, kagome-lattice Co₃Sn₂S₂ hosts a plethora of exotic quantum phenomena due to the interplay between magnetism, electronic correlations, and non-trivial band topology. However, achieving high crystal quality, which is crucial for understanding intrinsic mechanisms and enhancing the physical properties, still remains a significant challenge. Here, the synthesis of ultra-high-quality Co₃Sn₂S₂ single crystals is reported via an iterative chemical vapor transport (iterative-CVT) approach, achieving gigantic anomalous Hall conductivity (AHC) of 1600 Ω⁻¹cm⁻¹, anomalous Hall angle (AHA) of 40%, and exceptional carrier mobility and magnetoresistance of 10 490 cm² V⁻¹ s⁻¹ and 2500%. Intriguingly, a striking 65% enhancement of the AHC is observed upon increasing the temperature from 2 to 50 K, attributed to the presence of bipolar carrier contributions from the Weyl bands. Furthermore, an ultra-narrow flat band near the Fermi level is directly visualized by angle-resolved photoemission spectroscopy, suggesting enhanced electron correlations that render the electron concentration and hence AHC highly temperature-dependent. The findings provide a robust material platform to inspire further research into emergent quantum phenomena in magnetic kagome systems.