Superconducting and Magnetic Phase Boundaries in Doped Cu-Based Superconducting Oxides: Contrasting Charging and Pair Breaking Mechanisms

After several years of intensive study of the high transition temperature superconducting oxides (HTS), the nature and origin of the pairing mechanism has eluded investigators. Theories with local, real space pairing and more conventional models with k-space pairing have evolved and a variety of mechanisms have been proposed.1–5 A useful and now well known method of probing the relevant interactions in both low and high temperature superconductivity is through the use of impurities selected to investigate specific aspects of the response of the system to controlled perturbations, with particular emphasis given to changes of the superconducting properties.