Spin-Polarized Current in Coulomb Blockade and Kondo Regime
P. Ogrodnik
Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland
Full Text PDF
Received: 9 06 2007;
Spin-polarized electron transport through a single-level quantum dot attached to ferromagnetic and non-magnetic leads is studied with the use of the non-equilibrium Green function technique. Current polarization is investigated in dependence on parameters which characterize the device: the lead's polarization, a position of the dot energy level compared to the Fermi level in electrodes, and the Zeeman splitting of the dot level in an external magnetic field applied to the dot. Calculations were performed in two transport regimes: the Coulomb blockade regime with correlation effects treated within the Hartree-Fock approximation and the Kondo regime with a more rigorous approach to many-body effects at low temperatures.
DOI: 10.12693/APhysPolA.112.295
PACS numbers: 73.23.-b, 73.21.La, 85.75.-d