In this paper, we present theoretical investigation of the zero-frequency
shot noise spectra in electron tunneling through an interacting quantum dot
connected to two ferromagnetic leads with possibility of spin-flip scattering
between the two spin states by means of the recently developed bias-voltage and
temperature dependent quantum rate equations. For this purpose, a
generalization of the traditional generation-recombination approach is made for
properly taking into account the coherent superposition of electronic states,
i.e., the nondiagonal density matrix elements. Our numerical calculations find
that the Fano factor increases with increasing the polarization of the two
leads, but decreases with increasing the intradot spin-flip scattering.Comment: Some typos correction. 6 pages, 3 figures, based on work presented at
the 2004 IEEE NTC Quantum Device Technology Workshop, accepted for
publication by IEEE transactions on Nanotechnolog