Regulating Phase Slip Centers in Nanostructured Au-Ag films

1D and 2D superconductors show finite resistance below transition temperature due to the occurrence of phase slip centers in the current carrying path. Au-Ag nanostructured films have been posited as candidate materials for supporting superconductivity in the ambient that furthermore are prone to phase slip behavior. In this paper we study phase slip centers in Au-Ag nanostructured films and employ these to characterize disorder in these materials as well as to improve upon film quality. As prepared Au-Ag films were characterized through techniques such as XRD, SEM, TEM and UV-Vis optical spectroscopy. Current-voltage curves of Au-Ag films at specific temperatures exhibit discrete step-like behavior consistent with the existence of phase slip centers as reported previously. We analyze the observed response to determine film disorder. Systematic improvements in film processing enabled us to regulate phase slip behavior in Au-Ag films. Charge imbalance lengths as large as 0.36 microns are observed as a consequence of our refinements that are over two orders of magnitude greater than previous reports on the system. Engineering phase slip centers in these materials paves their use in bolometric devices as well as in single photon detectors.