Commensurate states in disordered quasiperiodic networks

In this paper, we report measurements of the normal-metal-superconductor phase boundary T c (H) in disordered quasiperiodic wire networks. The initially ordered network is an eightfold quasiperiodic array of the type previously constructed by Ammann, and several types of disorder have been introduced. One series of arrays is areally disordered by stretching and contracting individual worm segments in the network, and the resulting phase boundary exhibits a gradual decay of all phase-boundary structure with increasing field. A second series is perturbed by phason disorder, which amounts to the local flipping of small symmetric clusters of tiles and destroys the local ordering inherent in the inflation symmetry of the ordered network