Large anomalous Hall effect induced by local disorder in the kagome ferrimagnet TbMn6Sn6

The kagome ferrimagnet family RMn6Sn6 (R = Gd - Er) features Chern-gapped Dirac points in the band structure, theoretically allowing a large anomalous Hall effect. However, the experimentally observed anomalous Hall effect in RMn6Sn6 is only comparable to those found in conventional ferromagnets. Here, we report a significant enhancement of anomalous Hall effect in the kagome ferrimagnet TbMn6Sn6 induced by local disorder through Mg substitution on Tb. By electrical transport and anomalous Nernst effect measurements, combined with first-principles calculations, we demonstrate that the Mg substitution modulates the band structure of TbMn6Sn6, leading to an increase in intrinsic anomalous Hall conductivity. Additionally, the modulated band structure enhances the longitudinal conductivity, further boosting the extrinsic anomalous Hall conductivity dominated by skew scattering. Consequently, the total anomalous Hall conductivity reaches 950ω-1cm-1, entering the regime of topological magnets. Both of the large intrinsic and extrinsic anomalous Hall conductivity can be attributed to the nontrivial band structure near the Fermi level.