Dimensional crossover in the upper critical field of layered superconductors

Using the recently introduced g3 model for layered superconductors, we calculate the angular and temperature dependence of the upper critical field Hc2. By lowering the temperature we find a crossover from three-dimensional bulk behavior to decoupled two-dimensional layers in both the temperature and angular dependence of Hc2. This behavior is remarkably consistent with recent experiments and the comparison with the measured angular dependence provides an estimate for the interlayer coupling g3. © 1993 The American Physical Society.