Electron-spin polarization in a nanostructure modulated by the periodic bias

In this paper, we theoretically study the spin-dependent electron transport in a nanostructure modulated by the periodic bias. It is found that the number of the periodic bias strongly affects the electron transport properties. For the number of the periodic bias, m>1, the spin-splitting appears in each resonant domain, and the number of the spin-splitting peaks in each resonant domain is m-1. With increasing the number of periods, the resonance splitting increases, thus the number of the resonance peaks is increasing and the peaks become sharper as well as the spin-polarization is enhanced, although the average magnetic field of the nanostructure is zero.