A new kinetic term in the phenomenology of layered superconductors

Abstract

We show that the Lawrence-Doniach free energy for layered superconductors can be derived from an anisotropic Ginzburg-Landau free energy with a spatially dependent coefficient for the quadratic term. Our derivation indicates that new terms are present as well, including couplings of the gradients of the order parameters of neighboring layers. These terms tend to make the sign of the order parameters alternate from layer to layer, and may cause a phase transition in the presence of magnetic fields normal to the layers. © 1993.