Reorientable Spin Direction for Spin Current Produced by the Anomalous Hall Effect

Generating spin currents with controllable spin direction is important to spin-torque technology, which includes spin-based computing and magnetic random-access memory, but it is difficult to produce such currents through conventional means, like the spin Hall effect. This study shows that the anomalous Hall effect can be used to yield spin currents with controllable spin polarization. The magnetization of the generating ferromagnetic layer, and hence the spin polarization, is governed by exchange bias and external field. This result offers a great deal of flexibility in creating spin torque, which should enable innovative device designs.