Large thermal Hall effect in MnPS3.

Recent studies have demonstrated that the thermal Hall effect (THE) can originate from magnons (magnon Hall effect), phonons (phonon Hall effect), or their combination (magnon-polaron Hall effect). The magnon-polaron Hall effect, first observed in Fe₂Mo₃O₈, is particularly intriguing as its thermal Hall signal can be remarkably large. In this study, we explore the THE in MnPS₃, an insulating antiferromagnetic material exhibiting a spin-flop (SF) transition and significant magnetoelastic coupling, making it a strong candidate for studying the THE originating from spin-lattice coupling. We report an exceptionally large thermal Hall angle down to 4 K and show that it cannot be accounted for by standard calculations based on the intrinsic magnon-polaron Berry curvature. Our findings provide an in-depth analysis of the role of the SF transition in the thermal properties of MnPS₃and call for further theory development on magnon-phonon coupling and scattering to reveal their influence on transverse heat transport.