https://doi.org/10.1140/epjb/e2009-00144-1
Electrical generation of pure spin current with oscillating spin-orbit interaction
Department of Physics, Southeast University, 210096, Nanjing, P.R. China
Corresponding author: a lf_125s@foxmail.com
Received:
16
November
2008
Revised:
11
February
2009
Published online:
25
April
2009
We propose an electrical scheme for the generation of a pure spin current without a charge current in a two-terminal device, which consists of a scattering region of a two-dimensional electron gas (2DEG) with Rashba (R) and/or Dresselhaus (S) spin-orbit interaction (SOI) and two normal leads. The SOI is modulated by a time-dependent gate voltage to pump a spin current. Based on a tight-binding model and the Keldysh Green's function technique, we obtain the analytical expression of the spin current. It is shown that a pure spin current can be pumped out, and its magnitude could be modulated by device parameters such as the oscillating frequency of the SOI, as well as the SOI strength. Moreover, the spin polarisation direction of the spin current could also be tuned by the strength ratio between RSOI and DSOI. Our proposal provides not only a fully electrical means to generate a pure spin current but also a way to control the spin polarisation direction of the generated spin current.
PACS: 85.75.-d – Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields / 72.25.-b – Spin polarized transport / 73.23.-b – Electronic transport in mesoscopic systems / 73.63.-b – Electronic transport in nanoscale materials and structures / 72.25.Dc – Spin polarized transport in semiconductors
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2009
