Metallic conduction and superconductivity in the pseudogap phase

We analyze the t−J model on a square lattice using bosonic spinons and fermionic holons. Spinons are paired into singlets, which condense below a temperature T ∗. Metallic conduction and d-wave superconductivity result from separate, sublattice-preserving, holon hopping processes which originate from coupling with the condensate. Holons form a charge Fermi liquid, becoming incoherent (confined) above T ∗. In the superconductor holons hop as pairs, reducing kinetic energy. The two-sublattice property is the glue that connects the three phases; its effect can be seen in various correlation functions. The theory can account for many features of the cuprate superconductors, including the origin of two-dimensional metallicity.