The interlayer transport in a two-dimensional superconductor can reveal a peak in the temperature as well as the magnetic field dependence of the resistivity near the superconducting transition. The experiment was performed on the highly anisotropic misfit-layer superconductor $\left(\mathrm{LaSe}{)}_{1.14}\right({\mathrm{NbSe}}_2)$ with $T_c$ of 1.2 K. The effect is interpreted within the tunneling mechanism of the charge transport across the Josephson-coupled layers via two parallel channels—the quasiparticles and the Cooper pairs. Similar behavior can be found in the high- $T_c$ cuprates but there it is inevitably interfering with the anomalous normal state. The upper critical magnetic field can be obtained from the interlayer tunneling conductance.

• Received 5 March 2001

DOI:https://doi.org/10.1103/PhysRevLett.86.5990