  Spin-orbit coupling enables charge currents to give rise to spin currents and
vice versa, which has applications in non-volatile magnetic memories, miniature
microwave oscillators, thermoelectric converters and Terahertz devices. In the
past two decades, a considerable amount of research has focused on electrical
spin current generation in different types of nonmagnetic materials. However,
electrical spin current generation in ferromagnetic materials has only recently
been actively investigated. Due to the additional symmetry breaking by the
magnetization, ferromagnetic materials generate spin currents with different
orientations of spin direction from those observed in nonmagnetic materials.
Studies centered on ferromagnets where spin-orbit coupling plays an important
role in transport open new possibilities to generate and detect spin currents.
We summarize recent developments on this subject and discuss unanswered
questions in this emerging field.
