Electrical spin injection and detection in lateral all-semiconductor devices

Both electrical injection and detection of spin-polarized electrons are demonstrated in a single wafer allsemiconductor GaAs-based lateral spintronic device, employing p+Ga,Mn As /n+-GaAs ferromagnetic Esaki diodes as spin aligning contacts. Spin-dependent phenomena, such as spin precession and spin-valve effect, are observed in nonlocal signal and the measurements reveal the unusual origin of the latter in the investigated devices. The conversion of spin-polarized holes into spin-polarized electrons via Esaki tunneling leaves its mark in a bias dependence of the spin-injection efficiency, which at maximum reaches the value of 50%.