A spin Esaki diode

We demonstrate electrical electron spin injection ia interband tunneling, in ferromagnetic/nonmagnetic semiconductor Esaki diodes. An interband tunnel junction between ferromagnetic p(+)-(Ga.Mn)As and no nonmagnetic n(+)-GaAs under reverse-bias allows spin-polarized tunneling of electrons from the valence band of (Ga, Mn) As to the conduction band of n(-) -GaAs. The spin polarization of tunneled electrons is probed by circular polarization of electroluminescence (EL) from all n-GaAs/InGaAs/ p-GaAs light emitting structure integrated with the diode. Clear hysteresis loop with +/-6.5% remanence is observed in the magnetic-field dependence of the EL polarization at 6K, below the curie temperature of(Ga,Mn)As.