Critical behavior of a layered-superconductor model

We have performed a Wilson-Kogut renormalization-group study of Kosterlitz-Thouless-Berezinskii (KTB) layers coupled to one another by a Lawrence-Doniach-type term, in zero field. The recursion relations that we derive are valid when the interlayer coupling is weak and correctly reduce to the recursion relations for the KTB transition when =0. We find that there is crossover away from the two-dimensional KTB behavior and that the size of the upward shift in the transition temperature and the critical region are weakly dependent on . We apply our findings to layered high-temperature superconductors and conclude that their critical behavior at zero field is explained by our model.