Spin polarized and degenerate tunneling spectra in intrinsic Josephson junctions of Bi2212

Tunneling characteristics of HgBr2 intercalated superconducting Bi2212 single crystals have been obtained by using 10x10 mu m(2) intrinsic Josephson junction stacks, so called mesa structures. The spin degenerate current is driven along the c-axis with Au layer using point contact tunneling assembly at 4.2 K. The spin polarized current is also driven along the c-axis of crystals with Au/Co/Au multilayer. In order to understand the role of ferromagnetic layer (Co), quasiparticle branches are examined with and without magnetic field. The magnetic field evolution of switching currents are obtained for gaining further insight about the spin injection through the stack. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinbeim.