  We have found that the current rectification effect in triple layer (double
barrier) (Ga,Mn)As magnetic tunnel junctions strongly depends on the
magnetization alignment. The direction as well as the amplitude of the
rectification changes with the alignment, which can be switched by
bi-directional spin-injection with very small threshold currents. A possible
origin of the rectification is energy dependence of the density of states
around the Fermi level. Tunneling density of states in (Ga,Mn)As shows
characteristic dip around zero-bias indicating formation of correlation gap,
the asymmetry of which would be a potential source of the energy dependent
density of states.
