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arXiv · 2509.15644

Intrinsic Berry Curvature Driven Anomalous Hall and Nernst Effect in Co$_2$MnSn

Bishal Das·Arnab Bhattacharya·Amit Chanda·Chanchal K. Barman·Jadupati Nag·Hariharan Srikanth·Aftab Alam·I. Das
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Abstract

Magnetic topological semimetals often exhibit unusual electronic and thermal transport due to nontrivial bulk band crossings, enabling simultaneous realization of large anomalous Hall and Nernst conductivities ($\sigma_{xy}$ and $\alpha_{xy}$). Here, a comprehensive experimental and theoretical study of the anomalous transport properties of ferromagnetic Co$_2$MnSn is reported. First-principles calculations reveal topological Weyl points producing significant Berry curvature, driving dominant intrinsic anomalous Hall/Nernst effects. Electronic and thermal transport measurements demonstrate robust anomalous transport with substantial conductivity values that persist at room temperature ($\sigma_{xy}\sim$ 500 S/cm, $\alpha_{xy}\sim$ 1.3 A/m/K). We also show how the chemical substitution (via tuning Fermi level) can boost these effects (up to $\sigma_{xy}\sim$ 1376 S/cm, $\alpha_{xy}\sim$ 1.49 A/m/K at 150 K). These findings position Co$_2$MnSn as a compelling platform for exploring topological transport phenomena and advancing next-generation thermoelectric and spintronic technologies.

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Bishal Das, Arnab Bhattacharya, Amit Chanda, Chanchal K. Barman, Jadupati Nag, Hariharan Srikanth, Aftab Alam, I. Das. 2025-09-19. Intrinsic Berry Curvature Driven Anomalous Hall and Nernst Effect in Co$_2$MnSn. https://doi.org/10.1002/smll.202600063

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