Search

We theoretically investigate the dwell time for electrons in an antiparallel double $\delta $ -magnetic-barrier nanostructure, which is constructed on the surface of the InAs/Al x In1- x As heterostructure by patterning two ferromagnetic (FM) stripes. It is shown that the dwell time is dependent on electron spins due to the spin–field interaction between spins and magnetic fields. It is also shown that both magnitude and sign of the spin polarization in the dwell time can be modulated by the structural width or magnetic-strength difference between two magnetic barriers, which may give rise to a controllable temporal spin splitter for spintronics device applications.

We theoretically explore dwell time for electrons in a semiconductor microstructure, which is constructed on the surface of the InAs/Al x In1- x As heterostructure by patterning a ferromagnetic (FM) stripe and a Schottky-metal (SM) stripe in a parallel configuration. Dwell time is found to be dependent on electron spins. Spin-polarized dwell time can be controlled by changing an applied voltage to SM stripe. Thus, electron spins can be separated in time dimension, and such a semiconductor microstructure can be used as an electrically tunable temporal spin splitter for spintronics device applications.

The dwell time of electrons in a parallel double δ-magnetic-barrier (MB) nanostructure constructed by patterning an asymmetric ferromagnetic stripe on both the top and bottom of an InAs/AlxIn1−xAs heterostructure is calculated. Because the electron spins interact with the structural magnetic fields, the dwell time depends on the electron spins. Moreover, both the magnitude and sign of the spin-polarized dwell time can be modified by changing the magnetic field, the applied voltage, and the separation between the two δ-MBs. The electron spins can thus be separated in the time dimension, and such a magnetic nanostructure could serve as a controllable temporal spin splitter for use in spintronics device applications.

Based on a magnetically confined GaAs/Al x Ga1– x As microstructure modulated by spin-orbit coupling (SOC), we propose a controllable electron-spin filter for spintronics applications. This device operates due to both Zeeman interaction and Rashba or Dresselhaus SOC. Its spin polarization can be tuned by changing interfacial confining electric field or engineering strain.

We report a theoretical investigation on Goose-Hänchen (GH) effect for spin electrons across a magnetically confined GaAs/AlxGa1-xAs microstructure modulated by spin-orbit coupling [(SOC), including Rashba and Dresselhaus types]. An intrinsic symmetry in the device is broken by SOC, which gives rise to a considerable spin polarization effect in GH shifts of electrons. Both magnitude and direction of spin polarization can be manipulated by Rashba or Dresselhaus SOC, i.e., interfacial confining electric field or strain engineering. Based on such a semiconductor microstructure, a controllable spatial spin splitter can be proposed for spintronics applications.

The magnetically confined semiconductor heterostructure (MCSH) is often used as the momentum filter due to an essentially 2-D process for the electronic tunneling. Taking a typical MCSH into account, we theoretically investigate how to manipulate such momentum filters by the $\delta $ -doping technique. The momentum-filtering efficiency can be tuned because of the $\delta $ -doping dependence of the electron transmission. The involved MCSH can be employed as a controllable momentum filter.

We theoretically explore to separate electron-spins by dwell time of electrons through a magnetic microstructure with a δ-doping, which is fabricated on surface of InAs/AlxIn1-xAs heterostructure by patterning a ferromagnetic (FM) stripe. It is shown that dwell time is spin related due to both spin-field interaction and broken symmetry. It is also shown that spin-polarized dwell time can be manipulated structurally because of δ-doping dependent effective potential. Therefore, electron spins can be separated in time dimension and such a magnetic microstructure can serve as a controllable temporal spin splitter.

We propose a giant magnetoresistance (GMR) device, which can be experimentally realized by depositing two ferromagnetic (FM) strips and a Schottky metal (SM) stripe in parallel configuration on top of the GaAs heterostructure. The GMR effect ascribes a significant electron transmission difference between the parallel and antiparallel magnetization configurations of two FM stripes. Moreover, the MR ratio depends strongly on the magnetic strength of the magnetic barrier (MB) and the electric barrier (EB) height induced by an applied voltage to the SM stripe. Thus, this system can be used as a GMR device with tunable MR by an applied voltage to SM stripe or by magnetic strength of the MB.

We report a theoretical study on spin-polarized transport in a δ-doped magnetic-electric-barrier nanostructure, which can be realized in experiments by depositing two ferromagnetic stripes on top and bottom of a semiconductor heterostructure under an applied voltage and by using atomic layer doping technique. The spin-polarized behavior of the electron in this device is found to be quite sensitive to the δ-doping. One can conveniently tune the degree of the electron spin polarization by adjusting the weight and/or position of the δ-doping. Thus, the involved nansosystem can be employed as a controllable spin filter, which may be helpful for exploiting new spin-polarized source for spintronics applications.