Ginzburg-Landau impurity terms for unconventional superconductors

The Ginzburg-Landau theory of superconductivity provides expressions for the free energy and the supercurrent in terms of a spatially varying order parameter. In the presence of a single impurity, these expressions and the differential equation for the order parameter are supplemented by additional terms. We compute these extra terms using microscopic theory. Our calculation is very general, covering any (k) over cap-dependent order parameter Delta((k) over cap) which transforms according to a one-dimensional irreducible representation of the crystalline point group.