title: Kondo effect in quantum dots coupled to ferromagnetic leads.
abstract: We study the Kondo effect in a quantum dot coupled to ferromagnetic leads and analyze its properties as a function of the spin polarization of the leads. Based on a scaling approach, we predict that for parallel alignment of the magnetizations in the leads the strong-coupling limit of the Kondo effect is reached at a finite value of the magnetic field. Using an equation of motion technique, we study nonlinear transport through the dot. For parallel alignment, the zero-bias anomaly may be split even in the absence of an external magnetic field. For antiparallel spin alignment and symmetric coupling, the peak is split only in the presence of a magnetic field, but shows a characteristic asymmetry in amplitude and position.
authors.affiliation: Institut für Theoretische Festkörperphysik, Universität Karlsruhe, 76128 Karlsruhe, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Martinek
authors.forename: Y
authors.initials: Y
authors.lastname: Utsumi
authors.forename: H
authors.initials: H
authors.lastname: Imamura
authors.forename: J
authors.initials: J
authors.lastname: Barnaś
authors.forename: S
authors.initials: S
authors.lastname: Maekawa
authors.forename: J
authors.initials: J
authors.lastname: König
authors.forename: G
authors.initials: G
authors.lastname: Schön