Electron-spin polarization in ferromagnetic semiconductors

Using the single-site approximation for the s-f model, the electron-spin polarization (ESP) in ferromagnetic semiconductors is studied theoretically. Assuming that the difference between the results of photoemitted ESP and those of field-emitted ESP is due to the difference in the energies of emitted electrons, the dependence of ESP on the temperature, external magnetic field, and energy, which is observed experimentally, can be explained consistently.