  The spin filtering effect in the bilayer nanowire with quantum point contact
is investigated theoretically. We demonstrate the new mechanism of the spin
filtering based on the lateral inter-subband spin-orbit coupling, which for the
bilayer nanowires has been reported to be strong. The proposed spin filtering
effect is explained as the joint effect of the Landau-Zener inter-subband
transitions caused by the hybridization of states with opposite spin (due to
the lateral Rashba SO interaction) and the confinement of carriers in the
quantum point contact region.
