Superconductivity from a pseudogapped normal state:: A mode-coupling approach to precursor superconductivity

We derive a phase diagram for the pseudogap onset temperature T* (associated with the breakdown of the Fermi-liquid state, due to strong pairing correlations) and the superconducting instability T-c as a function of variable pairing strength g. Our diagrammatic approach represents a systematic application of the pairing decoupling scheme of Kadanoff and Martin to arbitrary g and temperatures T>T-c. This self-consistent, conserving scheme reveals a delicate competition between the growth (with increasing g) of the pseudogap magnitude and that of T-c. [S0163-1829(99)03802-3].