Josephson current and dissipation of the c-axis transport in magnetic fields in Bi₂Sr₂CaCu₂O_8+δ

We have measured the c-axis resistivity, magnetoresistance, current-voltage characteristics, and the maximum Josephson current I_c in magnetic fields H parallel to the c axis for a very thin mesa of a Bi₂Sr₂CaCU₂O_8+δ crystal, which is equivalent to 20 tunnel Josephson junctions in series. It is found that I_c decreases proportionally to H^-1, which agrees with a recent theory and Josephson plasma resonance experiments. This provides a basis for the straightforward application of the Ambegaokar-Halperin theory to the dissipation mechanism of the c-axis transport.