High-temperature superconductors: a structural-electronic model

Abstract

An enormous amount of effort has been expended in recent years in attempts to understand the fascinating properties of that class of complex copper oxides which are high-temperature superconductors. This activity has led to the generation of an unprecedented level of chemical and structural detail concerning this rather small region of the periodic table, renewed interest in the physics behind metal-insulator transitions in general, and a renaissance in the area of superconductivity itself. (For several years investigations had labored under the prediction that 30 K was probably the highest {Tc} attainable). In spite of this activity, identification of the essential piece of the physics is lacking. This is puzzling since the magnitude of the effect, the high {Tc}`s, should make this a rather straightforward phenomenon to explain. This Account will briefly summarize some of the salient features of the structural-electronic problem in the cuprates and will present a view of the electronic structure of these materials which may well be the chemical piece needed to complete the physical jigsaw puzzle.