Intrinsic Berry Curvature Driven Anomalous Hall and Nernst Effect in Co₂MnSn

Magnetic topological semimetals exhibiting unusual electronic and thermal transport due to nontrivial bulk band crossings, enabling simultaneous realization of large anomalous Hall ( ${\sigma }_{xy}^A$ ) and Nernst ( ${\alpha }_{xy}^A$ ) conductivities, are rare. Here, a comprehensive experimental and theoretical study of the anomalous transport properties of ferromagnetic ${\mathrm{Co}}_2\mathrm{MnSn}$ is reported. First-principles calculations reveal that Weyl points proximate to the Fermi level generate substantial intrinsic Berry curvature, which solely governs the intrinsic anomalous Hall and Nernst responses, in sharp contrast to the nodal-line-dominated behavior observed in lighter analogues of ${\mathrm{Co}}_2\mathrm{MnX}$ family. Electronic and thermal transport measurements demonstrate robust anomalous transport with substantial conductivity values that persist at room temperature ( ${\sigma }_{xy}^A\sim$  500 S  ${\mathrm{cm}}^{-1}$ , ${\alpha }_{xy}^A\sim$  1.3 A  $m^{-1}$   $K^{-1}$ ). We also show how Fermi level tuning, via chemical substitution, can boost these effects (up to ${\sigma }_{xy}^A\sim$  1376 S  ${\mathrm{cm}}^{-1}$ , ${\alpha }_{xy}^A\sim$  1.49 A  $m^{-1}$   $K^{-1}$ at 150 K). These findings position ${\mathrm{Co}}_2\mathrm{MnSn}$ as a compelling platform for exploring topological transport phenomena and advancing next-generation spin-caloritronic technologies.