Eur. Phys. J. B 68, 119-122 (2009)
https://doi.org/10.1140/epjb/e2009-00085-7

Spin-polarization and magnetoresistance in graphene-based resonant-tunnelling structures

College of Physics, Hebei Normal University, Shijiazhuang 050016, People's Republic of China and Hebei Advanced Thin Film Laboratory, 050016, Shijiazhuang, P.R. China

Corresponding author: ^a yxli@mail.hebtu.edu.cn

Received: 24 October 2008
Revised: 15 December 2008
Published online: 6 March 2009

Abstract

Spin-dependent transport of relativistic electrons through graphene based double barrier (well) structures with ferromagnetic electrodes have been theoretically investigated. Electron transmission with different spin states is strongly influenced by the incident wave vector, the height (depth) of the barrier and the separation between them. When the angle of the incident electrons is varied from zero to ±π/2, spin polarization varies from zero to 100% with characteristic oscillations that indicate spin anisotropy. Due to Klein tunnelling, spin-polarization is always zero for normal incident electrons; high spin-polarization only occurs at large incident angles. Because the resonance features in the spin-dependent transmission result from resonant electron states in wells or hole states in barriers, the conductance can reach e²/h in this resonant-tunnelling structure.