Observation of Berry Curvature‐Enhanced Anomalous Photo‐Nernst Effect in Magnetic Weyl Semimetal

ABSTRACT The anomalous Nernst effect is the thermoelectric counterpart of the anomalous Hall effect, which can emerge in magnetic materials or topological materials without a magnetic field. Such an effect is critical to both fundamental topological physics and various application fields, including energy harvesting, spintronics, and optoelectronics. In this work, we report the observation of the anomalous photo‐Nernst effect, which uses light excitation to generate temperature gradients for the thermoelectric response, and such an effect can be identified from a pronounced edge response in magnetic Weyl semimetal Co ₃ Sn ₂ S ₂ under zero magnetic field. Based on that, we report a clear enhancement on anomalous photo‐Nernst effect in the low‐photon‐energy region, originating from the topological contribution from the large Berry curvature of Weyl bands, by comparing the nominal anomalous Nernst coefficient under different wavelength excitations. The pronounced photo‐Nernst current benefits from the exceptional properties of Co ₃ Sn ₂ S ₂ , including the large thermoelectric coefficient, topologically enhanced anomalous response of Weyl bands, and the Shockley–Ramo nature of long‐range photocurrent generation. Our results reveal the interplay among light, magnetism, and topological order in magnetic Weyl semimetals, which not only offers insights for fundamental physics but also advances potential applications in quantum devices.