Spin Swapping Effect of Band Structure Origin in Centrosymmetric Ferromagnets

We show the spin swapping effect originated from band structure in centrosymmetric ferromagnets. Without breaking inversion symmetry or introducing spin-orbit impurities, the effect is attributed to anticrossings at which bands with different spin and different orbital are nearly degenerate, and thus has no analogue in nonmagnets. First-principle calculations for centrosymmetric 3d transition metal ferromagnets support the analysis based on analytic and tight-binding models and demonstrate the sizable spin swapping conductivity of band origin ~ 2500 (ħ/e)(Ωcm)
⁻¹
. Our theory generalizes the understanding on the transverse spin currents of ferromagnets and highlights the role of orbital degree of freedom in spin-orbit-coupled transport.