Theory of thermomagnonic torques in altermagnets

Abstract: We develop a theory of thermomagnonic torques in insulating altermagnets and predict a spin-splitter magnonic torque arising from the spin Seebeck effect. Additionally, we predict an anisotropic entropic torque. We study the effects of these torques on magnetic-texture dynamics and identify various anisotropic responses to temperature gradients. In particular, we predict spin-current-induced domain-wall precession, which can slow domain-wall motion for certain temperature-gradient directions. We also predict a temperature-gradient-driven anisotropic skyrmion Hall effect that enables fast skyrmion motion in response to thermal gradients. Our findings will be useful for spintronic applications such as magnetic racetrack memories and will serve as a hallmark of altermagnetism in insulating altermagnets with magnetic textures.