We present a simple device made of two small capacitively coupled quantum
dots in parallel. This set-up can be used as an efficient "Stern-Gerlach" spin
filter, able to simultaneously produce, from a normal metallic lead, two
oppositely spin-polarized currents when submitted to a local magnetic field.
Our proposal is based on the realization of a Kondo effect where spin and
orbital degrees of freedom are entangled, allowing a spatial separation between
the two spin polarized currents. In the low temperature Kondo regime, the
efficiency is very high and the device conductance reaches the unitary limit,
he2β per spin branch.Comment: 3 pages, 2 figure