Giant anomalous Hall conductivity in CeCoGe₃

Recently, we found that the heavy-fermion compound CeCoGe₃ exhibits a giant field-induced anomalous Hall conductivity (AHC). The values are not only exceeding those of other ferromagnetic materials like Fe-films, but also those of frustrated magnets like PdCrO₂. This presentation focuses on the intrinsic contribution to the AHC that is governed by the topological properties of a material. In CeCoGe₃ this contribution amounts to 2.5 x 10⁵ S/cm which is the largest value to have ever been reported. The intrinsic AHC arises due to either the real-space or the momentum-space Berry curvature, where the later can be computed from point- and line-like energy band crossings in the Brillouin zone near the Fermi surface. The existence of these so called Weyl nodes and nodal lines in CeCoGe₃ has been predicted by density functional theory calculations. We investigate whether the Weyl nodes and nodal lines could in fact explain the observed large AHC.