Thermally induced spin torque and domain-wall motion in superconductor/antiferromagnetic-insulator bilayers

We theoretically investigate domain-wall motion in an antiferromagnetic-insulator layer caused by thermally generated spin currents in an adjacent spin-split superconductor layer. An uncompensated antiferromagnet interface enables the two crucial ingredients underlying the mechanism—spin splitting in the superconductor and absorption of spin currents by the antiferromagnet. Treating the superconductor using the quasiclassical theory and the antiferromagnet via Landau-Lifshitz-Gilbert description, we find domain-wall propagation along the thermal gradient with relatively large velocities ∼100 m/s. Our proposal exploits the giant thermal response of spin-split superconductors in achieving large spin torques towards driving domain wall and other spin textures in antiferromagnets.