Structurally manipulating electron-spin polarization via δ-doping in a magnetic nanostructure

Abstract

We theoretically investigate the control of the electron-spin polarization in a spin filter by a tunalbe δ-doping, where the device and the δ-doping can be realized experimentally by depositing a ferromagnetic stripe on top of semiconductor heterostructure and using molecular beam epitaxy or metal-organic chemical-vapor deposition, respectively. The δ-doping dependent transmission and conductance are numerically calculated for InAs material system. It is shown that both amplitude and sign of electron-spin polarization vary dramatically with the weight and/or the location of the δ-doping. Thus, it is possible to open a new door for effectively manipulating spin-polarized source, and the considered nanostructure can serve as a spin filter with a structurally controllable spin polarization by the δ-doping.