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We theoretically investigate spin polarization for electrons in magnetically and electrically confined semiconductor microstructure, which is constructed by patterning a ferromagnetic stripe and a Schottky-metal stripe on top and bottom of GaAs/AlxGa1-xAs heterostructure, respectively. Both Zeeman interaction and spin–orbit coupling are taken into account; however, electron-spin polarization comes mainly from the latter due to a small effective g-factor for GaAs. Besides, both magnitude and sign of spin polarization can be manipulated by changing interfacial confining electric field or strain engineering, resulting in a tunable electron-spin filter for spintronics device applications.

We report a theoretical exploration on the control of the Dresselhaus －spin-orbit －coupling (SOC) induced spin polarization via the δ-doping for electrons in the 3-layered semiconductor heterostructure (3-LSH). It is shown that an obvious electron-spin polarization effect still exists when a δ-doping is introduced inside. Moreover, both magnitude and sign of the spin polarization can be controlled by adjusting the weight or position of the δ-doping. Therefore, spin-polarized electrons can be manipulated by the δ-doping technique, and the considered 3-LSH can be used as a structurally-controllable spin filter, which may be helpful for spintronics device applications.

We theoretically investigate the control of spin-polarized dwell time by δ-doping in a parallel double δ-magnetic-barrier nanostructure, which can be realized experimentally by depositing two asymmetric ferromagnetic stripes at the top and bottom of an InAs/Al x In1−x As heterostructure, respectively. Dwell time is still spin-polarized even if a δ-doping is included inside. Both the magnitude and the sign of the spin-polarized dwell time can be manipulated by changing the weight or position of δ-doping. Therefore, this nanostructure can be employed as a structurally controllable temporal spin splitter for spintronic device applications.

We propose to separate electron-spins by transmission time for electrons across a semiconductor microstructure. By calculating dwell time of electrons in a realistic magnetic microstructure, transmission time is found to be spin related, electron spins are, therefore, separated in time dimension. Besides, both magnitude and sign of spin-polarized dwell time can be manipulated by an applied voltage, which may give rise to an electrically-controllable temporal spin splitter for spintronics device applications.

Considering Dresselhaus-type spin–orbit coupling (SOC), we theoretically investigate spin-polarized transport in a 3-layered semiconductor heterostructure, InSb/InxGa1-xAs/GaSb. Adopting improved transfer matrix method to solve Schrodinger equation, electronic transmission coefficient is obtained exactly, and then spin polarization ratio is evaluated. An appreciable electron-spin polarization effect by the Dresselhaus-SOC appears in this layered semiconductor heterostructure. Spin polarization is associated closely with in-plane wave vector, incident direction and SOC strength. In particular, both magnitude and sign of spin polarization are manipulated by strain engineering or an appropriate intermediate-layer. Therefore, such a 3-layered semiconductor heterostructure can serve as a controllable spin filter for spintronics device applications.

In layered semiconductor heterostructure, there exists spin-orbit coupling (SOC), which can induce electron-spin polarization. Considering a realistic 3-layered semiconductor heterostructure, InSb/InxGa1-xAs/GaSb, we present a theoretical study of spin polarized transport by the Rashba-SOC type. An obvious electron-spin polarization effect is found in such a 3-layered system, and its degree is related to in-plane wave vector, Rashba-SOC strength and intermediate-layer parameters. Both magnitude and sign of spin polarization can be manipulated by tuning interfacial confining electric field or fabricating intermediate layer properly. These interesting features may be useful for exploring new way of spin injection and designing controllable spin filter for spintronics applications.