  Resonant tunneling of electrons between two ferromagnets and a quantum dot in
the presence of an externally applied magnetic field reveals a strong gate
dependence in the linear and nonlinear bias regime. This gate dependence
originates from the interplay between Coulomb interactions and spin-dependent
hybridization between the quantum dot and the leads. To take into account
Coulomb interaction strengths of the same order of magnitude as the external
magnetic field and the hybridization strength we adopt the numerically exact
iterative summation of path integrals (ISPI).
