Electric tunable of electron spin polarization in hybrid magnetic–electric barrier structures

2008 ◽  
Vol 372 (40) ◽  
pp. 6216-6220 ◽  
Author(s):  
Huaizhe Xu ◽  
Qiqi Yan
Keyword(s):  
Spin Polarization ◽  
Electron Spin ◽  
Electron Spin Polarization ◽  
Electric Barrier

Electron-spin polarization in both magnetically and electrically modulated nanostructures

2005 ◽  
Vol 83 (3) ◽  
pp. 219-227
Author(s):  
Mao-Wang Lu
Keyword(s):  
Spin Polarization ◽  
Electron Spin ◽  
High Energy ◽  
Electron Spin Polarization ◽  
Spintronic Devices ◽  
Spin Dependent Transport ◽  
73.40 Gk ◽  
Spin Polarization Effect ◽  
Dependent Transport ◽  
Electric Barrier

We investigate theoretically the spin-dependent transport properties of electrons in realistic magnetic-electric-barrier (MEB) nanostructures produced by the deposition, onto a heterostructure, of a metallic ferromagnetic stripe. We find the degree of electron-spin polarization to be closely tied to the voltage applied to the stripe, despite the fact that this voltage in itself induces no spin-polarization effect. As a positive (negative) voltage is applied, the electron-spin polarization shifts in the low- (high-) energy direction and increases (decreases). Our results imply that the degree of electron-spin polarization can be tuned through the applied voltage. This implication might prove useful in the design and application of spintronic devices based on magnetic-barrier nanostructures. PACS Nos.: 73.40.Gk, 73.23.-b, 75.70.Cn

ELECTRON-SPIN POLARIZATION IN BOTH MAGNETICALLY AND ELECTRICALLY-MODULATED NANOSTRUCTURES

2005 ◽  
Vol 12 (01) ◽  
pp. 67-74
Author(s):  
MAO-WANG LU
Keyword(s):  
Spin Polarization ◽  
Electron Spin ◽  
Applied Voltage ◽  
High Energy ◽  
Electron Spin Polarization ◽  
Spin Dependent Transport ◽  
Positive Voltage ◽  
Spin Polarization Effect ◽  
Dependent Transport ◽  
Electric Barrier

We theoretically investigate the spin-dependent transport properties of electrons in realistic magnetic-electric barrier nanostructures, which are produced by the deposition, on top of a heterostructure, of a metallic ferromagnetic stripe with an applied voltage. The degree of the electron-spin polarization is found to be closely associated with this voltage, although the use of applied voltage itself induces no spin polarization effect. As a positive voltage is applied to the stripe the electron-spin polarization shifts towards the low-energy region and increases; it shifts towards the high-energy direction and reduces for a negative applied voltage. These results shown in this work imply that the degree of electron-spin polarization can be tuned by means of an applied voltage on the stripes of system, which may result in a practical voltage-controlled spin filter.

Effects on the magnetic and optical properties of Co-doped ZnO at different electronic states

2017 ◽  
Vol 31 (31) ◽  
pp. 1750247
Author(s):  
Qingyu Huo ◽  
Zhenchao Xu ◽  
Linfeng Qu
Keyword(s):  
Absorption Spectrum ◽  
Spin Polarization ◽  
Electron Spin ◽  
Magnetic Moments ◽  
The State ◽  
Band Gaps ◽  
Electron Spin Polarization ◽  
Approximation Formula ◽  
Doped Zno ◽  
Co Doped

Both blue and red shifts in the absorption spectrum of Co-doped ZnO have been reported at a similar concentration range of doped Co. Moreover, the sources of magnetism of Co-doped ZnO are controversial. To solve these problems, the geometry optimization and energy of different Co-doped ZnO systems were calculated at the states of electron spin polarization and nonspin polarization by adopting plane-wave ultra-soft pseudopotential technology based on density function theory. At the state of electron nonspin polarization, the total energies increased as the concentration of Co-doped increased. The doped systems also became unstable. The formation energies increased and doping became difficult. Furthermore, the band gaps widened and the absorption spectrum exhibited a blue shift. The band gaps were corrected by local-density approximation + [Formula: see text] at the state of electron spin polarization. The magnetic moments of the doped systems weakened as the concentration of doped Co increased. The magnetic moments were derived from the coupling effects of [Formula: see text]–[Formula: see text]. The band gaps narrowed and the absorption spectrum exhibited a red shift. The inconsistencies of the band gaps and absorption spectrum at the states of electron spin polarization and nonspin polarization were first discovered in this research, and the sources of Co-doped ZnO magnetism were also reinterpreted.

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