A device for injecting spin polarized monochromatic electrons of a particular magnetic moment at room temperature and in absence of an external magnetic field into a nonmagnetic electrode comprising a ferromagnetic electrode, a nonmagnetic electrode spaced from said ferromagnetic electrode, a nanocrystal doped with a single paramagnetic ion disposed in the space between said electrodes, and an electrical connection between said electrodes for applying voltage to move the electrons from said ferromagnetic electrode, through said doped nanocrstal and into said nonmagnetic electrode.