Giant magnetoresistance in a two-dimensional electron gas modulated by magnetic barriers and the δ-doping

We theoretically investigate the modulation of the δ-doping to a semiconductor-based giant magnetoresistance (GMR) device, which can be realized experimentally by depositing two parallel ferromagnetic (FM) stripes on top and bottom of a GaAs/AlxGa1-xAs heterostructure. It is shown that a considerable GMR effect still exists in this device with the δ-doping. It is also shown that the magnetoresistance ratio (MR) depends on not only the weight but also the position of the δ-doping. These interesting results will be useful in understanding and designing structurally-controllable GMR devices for magnetic information storage.