  In this paper, we investigate the electronic transport properties of a
quantum dot (QD) connected to two ferromagnetic leads and one superconductor
lead in the Kondo regime by means of the finite-$U$ slave boson mean field
approach and nonequilibrium Green function technique. In this three-terminal
hybrid nano-device, we will focus our attention on the joint effects of the
Konod correlation, superconducting proximity pairing, and spin polarization of
leads. It is found that: the superconducting proximity effect will suppress the
linear local conductance (LLC) stemming from the weakened Kondo peak, and when
its coupling $\Gamma_s$ is bigger than the tunnel-coupling $\Gamma$ of two
normal leads, the linear cross conductance (LCC) becomes negative in the Kondo
region; for antiparallel configuration, increasing spin polarization further
suppresses LLC but enhances LCC, i.e. causing larger negative values of LCC,
since it is benefit for emergence of cross Andreev reflection; On the contrary,
for parallel configuration, with increasing spin polarization, the LLC descends
and greatly widens with the appearance of shoulders, and eventually splits into
four peaks, and meanwhile the LCC reduces relatively rapidly to the normal
conductance.
