An electron-spin filter was proposed by depositing a nanosized ferromagnetic metal stripe and a Schottky normal metal stripe on the top of the semiconductor hetero-structure. Based on transfer-matrix method, we investigate the effect of bias on electron-spin polarization in the spin filter. By numerical simulations, we found that not only the amplitude of the electron-spin polarization but also its sign varies with the bias, giving rise to a bias-tunable spin filter. Keywords: Hybrid magnetic nanostructure; Bias; Spin polarization; Spin filter
