Controllable GMR device in a δ -doped, magnetically and electrically modulated, GaAs/AlxGa1−xAsGaAs/AlxGa1−xAs heterostructure

• The giant magnetoresistance (GMR) effect is investigated theoretically in a δ-doped magnetic-electric-barrier semiconductor nanostructure.
• An obvious GMR effect is found in such a nanostructure and its magnetoresistance ratio is tunable by the δ-doping.
• A structurally tunable GMR device can be obtained for magnetic information storage.

We report on a theoretical study of giant magnetoresistance (GMR) effect in a δ  -doped GaAs/AlxGa1−xAsGaAs/AlxGa1−xAs heterostructure modulated by two stripes of ferromagnetic metal and a stripe of Schottky metal in parallel configuration. The δ-doping dependent transmission and conductance of the device are calculated. It is shown that a considerable giant magnetoresistance (GMR) effect exists in this structure. It is also shown that the magnetoresistance ratio (MR) can be switched by the δ-doping. The underlying physical mechanism of the results is analysed in light of δ-doping-dependent tunneling process in the device.