Anomalous thermoelectric and thermal Hall effects in irradiated altermagnets

Abstract

We show that a $d$-wave altermagnet can be transformed into a Chern insulator by irradiating it with elliptically polarized light from a high-frequency photon beam. We further explore the intrinsic anomalous thermoelectric and thermal Hall effects in light-irradiated altermagnets. At low temperatures, the thermoelectric Hall coefficient exhibits a linear temperature dependence but vanishes within the energy gap between the conduction and valence bands near the $M$ point. However, it displays pronounced peaks and dips at the gap boundaries near both the $M$ and $Γ$ points, suggesting that thermoelectric Hall conductivity is a sensitive probe for these gapped regions. Similarly, the low-temperature thermal Hall coefficient, which also shows a linear temperature dependence, becomes quantized across the bandwidth, reflecting the underlying topological character of the light-induced Chern insulating phase. These results establish thermoelectric and thermal Hall transports as powerful signatures of topology in driven altermagnetic systems.