Anomalous Hall effect from gapped nodal line in the Co2FeGe Heusler compound

Full Heusler compounds with cobalt as a primary element show anomalous transport properties owing to the Weyl fermions and broken time-reversal symmetry. We present here the study of anomalous Hall effect (AHE) in the Co2FeGe Heusler compound. The experiment reveals anomalous Hall conductivity (AHC) -100 S/cm at room temperature with an intrinsic contribution of -78 S/cm. The analysis of anomalous Hall resistivity suggests the scattering independent intrinsic mechanism dominates the overall behavior of anomalous Hall resistivity. The first principles calculation reveals that the Berry curvature originated by a gapped nodal line near EF is the main source of AHE in the Co2FeGe Heusler compound. The theoretically calculated AHC is in agreement with the experiment.