Quantum dots attached to ferromagnetic leads: possibility of new spintronic devices

Transport of spin polarized electrons through a quantum dot attached to ferromagnetic leads is considered theoretically in the Hartree-Fock approximation. Transport characteristics of such a device strongly depend on magnetic configuration of the system. For suitable parameters one can obtain transport characteristics typical of diodes and/or spin valves. The diode-like features are particularly pronounced for collinear alignment of the magnetic moments, whereas they are partly suppressed in canted configurations.