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Recent theoretical calculations have shown that Mn₃Sn₂, a well-known magnetocaloric material with multiple magnetic transitions, possesses both nodal lines and nodal surfaces in its electronic structures, making it an excellent platform for studying anomalous transport properties in magnetic topological candidates. In this work, we performed comprehensive electrical, thermal, and thermoelectric measurements on Mn₃Sn₂ single crystals. The electrical resistivity (T) shows an abnormal peak near the Curie temperature, T₂₂227 K, and a negative resistivity slope above T₂₂, which are probably related to a large spin-fluctuation scattering. The Seebeck coefficient Sₗₗ (T) shows a sign reversal below 80 K although the Hall coefficient is always positive, which might be ascribed to the magnon-drag effect. Below T₂₁262 K, a significant anomalous Hall effect is observed, and the anomalous Hall resistance (ₗₘ^A) peaks at around 7 cm at 200 K. ₗₘ^A exhibits a quadratic dependence on the longitudinal resistivity ₗₗ, and the anomalous Hall conductivity ₗₘ^A remains nearly temperature independent below 200 K, suggesting the dominance of the intrinsic Berry-phase mechanism. Correspondingly, we also detect a large anomalous Nernst effect, with the anomalous Nernst coefficient reaching approximately 10. 16em{0ex}0. 16em{0ex}K^-1 at 200 K. Despite Mn₃Sn₂ exhibiting robust ferromagnetism, its anomalous Hall angle (2. 5%), anomalous Nernst angle (6. 5%), and large anomalous Nernst coefficient (1. 654pt{0ex}0. 16em{0ex}0. 16em{0ex}K^-10. 16em{0ex}T^-1) surpass those observed in typical ferromagnetic materials. Our results experimentally demonstrate the existence of topologically nontrivial states in Mn₃Sn₂.
Bai et al. (Fri,) studied this question.