  Electrical injection and detection of spin-polarized electrons is
demonstrated for the first time in a single wafer, all-semiconductor,
GaAs-based lateral spintronic device, employing p+-(Ga,Mn)As/n+-GaAs
ferromagnetic Esaki diodes as spin aligning contacts. The conversion of
spin-polarized holes into spin-polarized electrons via Esaki tunnelling leaves
its mark in a bias dependence of the spin-injection efficiency, which at
maximum reaches the relatively high value of 50%.
