Magnetic barrier in a two-dimensional hole gas

Transport properties of a magnetic barrier in a GaxAl1−xAs based two-dimensional hole gas are reported. A ferromagnetic cobalt film, separated by an AlOx layer from the semiconductor in order to prevent leakage currents, is magnetized in-plane, such that the fringe field generates a localized perpendicular magnetic field acting as a magnetic barrier. The resistance as a function of the in-plane magnetic field shows a characteristic minimum at the coercive field of the ferromagnetic film. Semiclassical simulations based on the Landauer-Büttiker formalism show good agreement with the experiment.