Thermal Hall Effect in Collinear Antiferromagnets on a Square Lattice*

We show that the thermal Hall effect is possible in collinear antiferromagnets on a squre lattice once the magnon-phonon interaction due to the Dzyaloshinskii-Moriya interaction (DMI) is taken into account. We discuss the field- and DMI-dependence of the thermal Hall coefficient. We show that the thermal Hall conductivity is controlled by the resonant contribution from the anticrossing points between the magnon and phonon branches, and estimate its size in real materials.