  We investigate spin-dependent quasiparticle and Cooper-pair transport through
a central node interfaced with two superconductors and two ferromagnets. We
demonstrate that voltage biasing of the ferromagnetic contacts induces
superconducting triplet correlations on the node and reverses the supercurrent
flowing between the two superconducting contacts. We further find that such
triplet correlations can mediate a tunable spin current flow into the
ferromagnetic contacts. Our key finding is that unequal spin-mixing
conductances for the two interfaces with the ferromagnets result in equal-spin
triplet correlations on the node, detectable via a net charge current between
the two magnets. Our proposed device thus enables the generation, control, and
detection of the typically elusive equal-spin triplet Cooper pairs.
