Origin and control of spin currents in a magnetic triplet Josephson junction

We study the appearance of a Josephson spin current in a model triplet superconductor junction with a magnetically-active tunnelling barrier. We find three distinct mechanisms for producing a spin current, and we provide a detailed discussion of the symmetry properties and the physical origins of each. By combining these three basic mechanisms, we find that it is possible to exercise fine control over the spin currents. In particular, we show that unlike the charge current, the spin currents on either side of the barrier need not be identical.