I have been working on lattice of superconducting grains and the corresponding phase oscillations. So, I would like to know about the literature on single impurity effects on this type of materials.
Lattice of identical grains? And what is the nature of the impurity? A magnetic object or a potential scatterer? And what is the role of the grain boundaries? With respect to the SC subsystems they could also be regarded as "impurities"... [but most probably aren't].