Pseudogaps, dopants, and strong disorder in cuprate high-temperature superconductors

Strong electronic nanoscale disorder is present in all cuprate high-temperature superconductors, interwoven with the microscopic mechanisms responsible for both the high superconductive transition temperatures and many normal state transport anomalies. Disorder is revealed most dramatically in high-resolution scanning tunnelling microscopy experiments, while its origins at the atomic level have been studied by several other techniques. The review reassesses the significance of many other ‘mean field’ experiments in the context of strong disorder, with emphasis on the effects of high-mobility dopants and long-range strain fields.