heterostructure*

It has been recognized that the condensation of spin-triplet Cooper pairs requires not only the broken gauge symmetry but also the spin ordering as well. One consequence of this is the possibility of the Cooper pair spin current analogous to the magnon spin current in magnetic insulators, the analogy extending to the existence of the Gilbert damping. The recently fabricated heterostructure of the thin film of the itinerant ferromagnet SrRuO₃ on the bulk SrR₂uO₄, the best-known candidate material for the spin-triplet superconductor, offers a promising platform for generating such spin current. We will show how such heterostructure allows us to not only realize the long-range spin valve but also electrically drive the collective spin mode of the spin-triplet order parameter. Our proposal represents both a new realization of the spin superfluidity and a transport signature of the spin-triplet superconductivity.