Europhys. Lett.
Volume 73, Number 6, March 2006
Page(s) 941 - 947
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 10 February 2006
Europhys. Lett., 73 (6), pp. 941-947 (2006)
DOI: 10.1209/epl/i2005-10472-8

Spin-polarized Andreev reflection tunneling through a precessing magnetic spin

Yao-Ming Shi1, Shi-Ping Zhou1, Xiu-Feng Cao1, Hao Huang1 and Hao Chen2

1  Department of Physics, Shanghai University - Shanghai 200444, PRC
2  Department of Physics, Fudan University - Shanghai 200433, PRC

received 13 September 2005; accepted in final form 16 January 2006
published online 10 February 2006

We study theoretically the spin-polarized Andreev reflection tunneling through a local precessing magnetic spin weakly coupled to a ferromagnet and to a superconductor. The linear Andreev reflection conductance is obtained at zero temperature by using a nonequilibrium Green function approach. It shows that the spin-exchange interaction on the local spin-site can result in two spin-coherent states, from which the Andreev reflection conductance resonance with either a double peak or a single peak is developed. We find that the spin-orbit interaction in the barrier between the local spin-site and the ferromagnet-electrode leads only to a conductance oscillation with base frequency twice the Larmor frequency, $2\omega _L$, and a variable amplitude with equilibrium chemical potential and spin-flip tunneling coupling.

73.63.-b - Electronic transport in nanoscale materials and structure.
85.75.-d - Magnetoelectronics; spintronics: devices exploiting spin-polarized transport or integrated magnetic fields.
73.40.Gk - Tunneling.

© EDP Sciences 2006