Manipulating spin beam splitter by electric field in hybrid ferromagnetic-Schottky-stripe and semiconductor nanostructure

Abstract

Recently, a spin beam splitter, which operates via the Goos–Hänchen (GH) effect of electrons, was fabricated by depositing ferromagnetic and Schottky metal stripes on top of a semiconductor heterostructure. To explore effective manipulation of its spin polarization of GH shifts, we introduce a transverse electric field into the device. Theoretical analysis and numerical simulation show that both magnitude and sign of the spin polarization are related closely to this electric field. Thus, this spin beam splitter can be used as an electrically controllable spin‐polarized source for spintronics applications.

Electrically-Controllable Spin Spatial Splitter in a Novel Magnetic Nanostructure

“…Clearly, it depends not only on the magnetic profile B z ðxÞ, the longitudinal wave vector k y , and the electronspin r, but also on the transverse electric fieldF x . As pointed out by Ma et al, 30 it is the dependence of the effective potential on the electric field that leads to the possibility to manipulate the spin spatial splitter. In the device region (ÀL=2 < x < L=2), the effective potential U eff ðx; k y ; r; F x Þ is linear with respect to the variable x, therefore, the reduced 1D Schrödinger equation (2) can be solved analytically with the help of Hermitian functions.…”

“…Therefore, such an electric field F x or a bias V a can't be too large to guarantee the usage of this theory, e.g., for V a ¼ 1:0 in dimensionless form, correspondingly, in SI units V a ¼ 0:48 meV. 30 …”

“…[25][26][27][28] It is well known that a tunable spin-polarized source is desired for spintronic applications. 29 More recently, taking the hybrid magnetic-electric-barrier nanostructure into account, Ma et al 30 proposed an idea to control the spin spatial splitter by the transverse electric field. Very recently, based on a novel magnetic nanostructure with a zero average magnetic field, another spin spatial splitter was reported.…”