Evidences of topological nodal line semimetal in Mn3GaC: Anomalous Hall effect, thermal transport and DFT studies

The non-trivial electronic transport in magnetic topological materials have attracted significant attention. Here, we present evidences of a topological nodal line semimetal in antiperovskite [Formula: see text]GaC along with the experimental studies such as the anomalous Hall effect (AHE), Kondo effect and thermal transport properties (Seebeck and Nernst effects). The upturn in the low-temperature electrical resistivity follows Hamann expression with the Kondo temperature [Formula: see text] = 16 K. The scaling analysis of the anomalous Hall conductivity ([Formula: see text]) suggests that the AHE in [Formula: see text]GaC is primarily governed by coexistence of both intrinsic Berry curvature and skew scattering mechanisms. The experimentally observed value of [Formula: see text] (∼ 50 [Formula: see text]) is close to the theoretically calculated value. The low temperature Seebeck data suggests the presence of significant contribution of electron-magnon scattering, and a large value of Nernst coefficient is consistent with finite Berry curvature effects in [Formula: see text]GaC. The electronic band structure calculations with spin-orbit coupling, shows the formation of a drumhead-shaped surface states, and the existence of finite number of Weyl nodes, in consistence with the experimental findings.