Pseudogap effects induced by resonant pair scattering

Abstract

We demonstrate how resonant pair scattering of correlated electrons above ${T}_{c}$ can give rise to pseudogap behavior. This resonance in the scattering $T$ matrix appears for superconducting interactions of intermediate strength, within the framework of a simple fermionic model. It is associated with a splitting of the single peak in the spectral function into a pair of peaks separated by an energy gap. Our physical picture is contrasted with that derived from other $T$-matrix schemes, with superconducting fluctuation effects, and with preformed pair (boson-fermion) models. Implications for photoemission and tunneling experiments in the cuprates are discussed.