Spin filtering through a double-bend structure
  We propose a simple scheme for the spin filter by studying the coherent transport of electrons through a double-bend structure in a quantum wire with a weak lateral magnetic potential which is much weaker than the Fermi energy of the leads. {\em Extremely large} spin polarized current in the order of {\em micro-Ampere} can be obtained because of the strong resonant behavior from the double bends. Further study suggests the roubustness of this spin filter. 
Q. W. Shi, J. Zhou, and M. W. Wu