Intrinsic spin currents in ferromagnets

We present first principles calculations showing that an applied electric field generates intrinsic spin currents in ferromagnets that flow perpendicularly to the electric field. Reduced symmetry in ferromagnets with spin-orbit coupling enable a wide variety of such spin currents. However, we find the total spin current is approximately given by the sum of a magnetization-independent spin current with the symmetry of the spin Hall effect and a spin-polarized anomalous Hall current. We also present a simple tight-binding model that captures the relevant physics. Intrinsic spin currents are not subject to dephasing, enabling their spin polarizations to be misaligned with the magnetization, which is crucial to explain the magnetization-independent spin Hall effect. The spin Hall conductivity and spin anomalous Hall conductivities of transition metal ferromagnets can be comparable to Pt, opening new avenues for efficient spin current generation in spintronic devices.