Spin-polarized currents driven by spin-dependent surface screening

We demonstrate the mechanism of spin current generation in ultrathin ferromagnetic film by voltage-induced interface magnetoelectric effect and provide a rigorous theoretical and numerical description of the phenomenon. Surprisingly, for MgO-Cu-Co-MgO systems the spin-dependent screening in thin (less than 20 nm) Co film produces spin accumulation 7 times higher than the accumulation induced by the bulk effect of spin-dependent conductivity in thick Co films. An experimental approach to validate our numerical predictions is proposed. The demonstrated effect opens routes to design highly miniaturized, voltage-controlled spintronic or magnonic devices, while the developed model is a useful tool to study spin currents driven by surface screening.