Conditions for the Spin Rectification Phenomena Predicted for Semiconducting Triple Barrier Structures in the Presence of the Rashba Spin-Orbit Coupling

We propose the fabrication of a spin rectifying diode that utilizes the Rashba spin-orbit coupling, by the application of semiconducting triple barrier structures. This spin diode makes use of spin-dependent resonant tunneling levels that are formed in the triple barrier structures. We found that, for a certain emitter-collector bias voltage, it is possible to engineer the structure in such a way that a resonant level formed within the first quantum well matches that of the second quantum well only for a selected spin state, thus realizing an electronic spin rectifier. The calculated spin-filter efficiency of the transmitted current through the device, which is defined as |I↑-I↓|/(I↑+I↓), is found to be higher than 99.9%.