In this work we report c-axis conductance measurements done on a superlattice based on a stack of 2 layers YBa2Cu3O{7-\delta} and 7 layers PrBa2Cu3O{7-\delta} (2:7). We find that these quasi-2D structures show no clear superconducting coupling along the c-axis. Instead, we observe tunneling with a gap of \Delta_c=5.0\pm 0.5 meV for the direction perpendicular to the superconducting planes. The conductance spectrum show well defined quasi-periodic structures which are attributed to the superlattice structure. From this data we deduce a low temperature c-axis coherence length of \xi_c=0.24\pm 0.03 nm.
@article{arxiv.cond-mat/0002066,
title = {c-Axis tunneling in YBa2Cu3O7-\delta/PrBa2Cu3O7-\delta superlattices},
author = {J. C. Martinez and A. Schattke and M. Jourdan and G. Jakob and H. Adrian},
journal= {arXiv preprint arXiv:cond-mat/0002066},
year = {2009}
}