  Conducting altermagnets have recently emerged as intriguing materials
supporting strongly spin-polarized currents without magnetic stray fields. We
demonstrate that altermagnets enable three key functionalities, merging
superconductivity and spintronics. The first prediction is a controllable
supercurrent-induced edge magnetization, which acts like a dissipationless
spin-splitter effect. The second and third predictions are a Cooper pair
spin-splitter and a filtering effect, respectively. These effects allow for
spatial separation of triplet pairs with opposite spin-polarizations and
spin-selective tunneling of Cooper pairs. We derive a quasiclassical theory
with associated boundary conditions that describe these phenomena and explain
how they can be experimentally verified. Our results open a new path for
spatial control of spin signals via triplet Cooper pairs using hybrid
superconductor-altermagnet devices.
