Interlayer tunneling model for thec-axis resistivity in high-temperature superconductors

The c-axis resistivity of ${\mathrm{Bi}}_2$ ${\mathrm{Sr}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_{\mathit{x}}$ single crystals shows a magnetic-field-dependent peak below the zero-field ${\mathit{T}}_{\mathit{c}}$. We find good agreement with the temperature and field dependence of the peak, by modeling the c-axis conduction as a series stack of Josephson tunnel junctions. For intermediate values of the Josephson coupling, we predict such a peak and verify it by measurements on discreet, thin-film Josephson junctions. The exaggerated effects in ${\mathrm{Bi}}_2$ ${\mathrm{Sr}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_{\mathit{x}}$ result from its unusually large energy gap and fluctuations.