Perovskite as a spin current generator

We theoretically show that materials with perovskite-type crystal structures provide a platform for spin current generation. Its mechanism is based on spin-split band structures in certain kinds of collinear antiferromagnetic states, requiring neither spin-orbit coupling nor a ferromagnetic moment. By investigating a multiband Hubbard model for transition-metal compounds by means of the Hartree-Fock approximation and the Boltzmann transport theory, we find that a pure spin current is induced by an electric field applied to a C-type antiferromagnetic metallic phase. The spin current generation originates from a cooperative effect of spatially anisotropic electron transfer integrals owing to the GdFeO3-type lattice distortion, which is ubiquitous in many perovskites, and the collinear spin configuration. We discuss our finding from the symmetry point of view, in comparison with other spin current generator candidates with collinear antiferromagnetism. We also propose several ways to detect the phenomenon in candidate perovskite materials.