How optimal inhomogeneity produces high temperature superconductivity

Before Vic Emery's untimely death, we had the privilege of working closely with him on the role of Coulomb frustrated phase separation in doped Mott insulators, and on the consequences of the resulting local electronic structures on the "mechanism" of high temperature superconductivity. In the present article, we discuss the resulting perspective on superconductivity in the cuprates, and on the more general theoretical issue of what sorts of systems can support high temperature superconductivity...