We designed and fabricated a spin ratchet at the single-electron level that produces spin currents with no net bias or charge transport. Our device is based on a single-electron transistor (SET) comprising a superconducting island connected to normal leads via tunnel barriers with different resistances that break spatial symmetry. We quantified the spin ratchet efficiency by using ferromagnetic leads with known spin polarization. For more information follow the link or click on “Research”.