Structurally-Controllable Electron-Spin Filter Based on a Hybrid Magnetic-Electric-Barrier Nanostructure Modulated by a δ-Doping

We report a theoretical investigation on manipulation of electron-spin filtering by delta-doping in a hybrid magnetic-electric-barrier nanostructure, which can be experimentally realized by the deposition, on top and bottom of the InAs/AlxIn1-xAs heterostructure, respectively, of a ferromagnetic stripe with a horizontal magnetization and a Schottky-metal stripe under an applied voltage. It is shown that, due to the spin-field interaction such a semiconductor nanostructure still possesses an obvious spin filtering effect even if a delta-doping is included inside. It is also shown that the degree of electron spin polarization can be manipulated by changing weight or position of the delta-doping. Therefore, this nanostructure can be employed as a structurally-tunable electron-spin filter for spintronics applications.