Depression of the interlayer Josephson coupling in Bi2Sr2CaCu2O8+x single crystals by spin-polarized current injection along the c-axis

Abstract

We studied the effect of spin-injection on tunneling conduction properties of intrinsic Josephson junctions (IJJs) formed in Bi2Sr2CaCuO8+x single crystals. Properties of an identical stack (10 x 5 x 0.030 mum(3)) of IJJs were compared for the bias current injection through An and Co electrodes. Clear quasiparticle branches in tunneling current-voltage (I-V) curves from the IJJs in the stack were observed for all unpolarized bias current through the Au electrode. Spin-injection through the Co electrode caused pair breaking in the CuO2 double layers, which led to reduction of the Josephson critical current and the superconducting gap revealed in the tunneling I-V curves. (C) 2004 Published by Elsevier B.V.