Spin-dependent transport and thermopower in ferromagnetic quantum point contacts

Using scattering matrix method, the spin-dependent conductance and thermopower in ferromagnetic quantum point contacts (QPCs) are calculated at a certain temperature. The results indicate that the exchange splitting energy removes the spin degeneracy and the spin-up and spin-down electrons have different contributions to the conductance and the thermopower. The odd integer multiples of the quantized conductance, G(0)(= e(2)/h), appear and the position of the peaks in thermopower shift correspondingly. (C) 2004 Elsevier B.V. All rights reserved.