Electron-spin polarization in magnetically modulated quantum structures

The spin-dependent electron resonant tunneling through magnetically modulat ed quantum structures has been investigated with and without an external el ectric field. The spin polarization is found to be strongly dependent on th e magnetic configuration, the applied bias, the incident electron energy, a nd the incident wave vector. It is shown that an unpolarized beam of conduc ting electrons can be strongly polarized for an electron tunneling through magnetic-barrier structures, which is an arrangement with unidentical magne tic barriers and wells. The external electric field greatly changes the spi n polarization of electrons for small electronic energies, where the electr on-spin polarization exhibits considerable wave-vector-dependent features.