title: Positive cross correlations in a three-terminal quantum dot with ferromagnetic contacts.
abstract: We study current fluctuations in an interacting three-terminal quantum dot with ferromagnetic leads. For appropriately polarized contacts, the transport through the dot is governed by dynamical spin blockade, i.e., a spin-dependent bunching of tunneling events not present in the paramagnetic case. This leads, for instance, to positive zero-frequency cross correlations of the currents in the output leads even in the absence of spin accumulation on the dot. We include the influence of spin-flip scattering and identify favorable conditions for the experimental observation of this effect with respect to polarization of the contacts and tunneling rates.
authors.affiliation: Department of Physics and Astronomy, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Cottet
authors.forename: W
authors.initials: W
authors.lastname: Belzig
authors.forename: C
authors.initials: C
authors.lastname: Bruder