  Spin polarized transport through a quantum dot coupled to ferromagnetic
electrodes with noncollinear magnetizations is discussed in terms of
nonequilibrium Green functions formalism in the finite-U slave boson mean field
approximation. The difference of orientations of the magnetizations of
electrodes opens off-diagonal spin-orbital transmission and apart from spin
currents of longitudinal polarization also spin-flip currents appear. We also
study equilibrium pure spin current at zero bias and discuss its dependence on
magnetization orientation, spin-orbit coupling strength and gate voltage.
Impact of these factors on tunneling magnetoresistance (TMR) is also
undertaken. In general spin-orbit coupling weakens TMR, but it can change its
sign.
