A spin transistor comprises a spin injector for injecting, from a first
nonmagnetic electrode carriers with a spin parallel to a spin band
forming the band edge of a first ferromagnetic barrier layer, to a second
nonmagnetic electrode layer, as hot carriers. It also comprises a spin
analyzer whereby, due to spin-splitting at the band edge of a second
ferromagnetic barrier layer, the spin-polarized hot carriers are
transported to a third nonmagnetic electrode when the direction of the
spin of the carriers injected into the second nonmagnetic electrode is
parallel to that of the spin of the spin band at the band edge of the
second ferromagnetic barrier layer, whereas the hot carriers are not
transported to the third nonmagnetic electrode in the case of
antiparallel spin. A memory element is also provided that comprises such
a spin transistor.