Cuprate phase diagram mystery
The properties of the cuprates vary with temperature (y-axis) and the doping per unit cell of CuO2 (x-axis). Theorists are unable to explain why the superconducting transition temperature (thick black line) is so high in the cuprates. However, if they could understand the behaviour of the cuprates in the pseudogap region (blue), they might be able to explain high-temperature superconductivity. The properties of the various other regions in the diagram are explained in the text.